As a Moments subpage, all spoilers are unmarked as per policy. You Have Been Warned.
- Leonard's Hilariously Abusive Childhood is, like Amy's past, funny but sad. For instance, he never had a birthday party as a kid, and he essentially had to give up his childhood to become the genius he is now. Poor guy.
- In "The Friendship Algorithm", Sheldon is at a bookstore looking for a book about making friends when he strikes up a conversation with a little girl. They get along, with Sheldon offering to take her to a zoo before Leonard drags him away because of how bad it looks. It's set up as a gag and it works as one, but it also fits here because we (the audience) know that, for all his quirks and annoying habits, Sheldon would never do something like that to her and she would probably be relatively safe with him. Child abduction and abuse are horrible, it's just people have to assume the worst even from someone who wouldn't even have a sexual encounter with a willing woman his age (Amy, Season 5). The absolute worst part: Sheldon was trying to learn how to make friends and that girl probably would've become a close friend (It's Sheldon, would it have been weirder than half the stuff he does?)
- Really, it was sad not because of the specific events but because it once again showcased that on an emotional level Sheldon isn't much older than that girl, which has been the source of most of the problems in his life.
- In the season finale, when Penny quietly admits to herself that she wishes Leonard wasn't going away for the whole summer to the North Pole.
- Sheldon's Star Trek-based fanscript in "The Thespian Complex," with him leaving his mother to go to the future and Penny insisted on reversing the roles (She would play Spock and Sheldon would play his mother). Sheldon's script was based on the idea that nobody appreciated him or his intelligence, but portraying his mother made him realize how much his mother loved him. Of course, this isn't stated out loud but in Sheldon having an emotional breakdown playing both his mother and his ten year old self.
- Whenever Amy's childhood is revealed, it's funny but usually kinda sad. For instance, she never had friends as a kid:
Penny: Wait, you've never been to a sleepover?
Amy: No, unless you count the time I had influenza and shared a hospital room with a little Vietnamese girl... She didn't make it through the night, but up till then it was kinda fun.
Penny: (choked up) Give her the corsage, Leonard.
- In "The Justice League Recombination", they go to the comic book store for the New Year's Eve party. When midnight strikes, Zack kisses Penny with her looking guiltily and sadly at Leonard. Leonard looks extremely sad as well, as if he was holding back tears. The Auld Land Syne theme doesn't help at all, it only makes the whole situation sadder.
- Leonard starts dating Priya in what looks like a very long term and serious relationship, so while Penny puts on a brave face you can tell that it's eating away at her that Leonard has moved on (with someone who was more compatible with him on paper as well) and she eventually breaks down in tears. It doesn't help that Amy was anticipating this all along the way and told her repeatedly that it was going to happen eventually, but the emotions that go on in such a scenario are hard to deal with.
- The entirety of Season 4 can be seen as one huge Tear Jerker for Leonard and Penny, they adjust to not being a couple anymore, however, Leonard is left heartbroken when seeing Penny kiss Zack during the aforementioned scene in the "The Justice League Recombination". Leonard's new relationship with Priya also forces Penny to realise how much Leonard really meant to her and she's left devastated over how she gave up her a relationship with him, a fact she confesses to Raj during the season finale.
- The season opening is very sombre as the group dynamic is badly damaged due to Raj and Penny sleeping together, Penny is left guilt-ridden over hurting Leonard and turns to alcohol to cope. Although Raj does reveal that he and Penny didn't actually have sex and just fell asleep, Penny still descends deeper into alcoholism over the loss of Leonard.
- Brent Spiner tearing open Sheldon's mint condition Wesley Crusher action figure autographed by Wil Wheaton, which had finally ended their rivalry, is kind of cruel when you think about it.
- Amy's isolation in "The Isolation Permutation" rings true, especially since her interactions with Penny made her ecstatic to be friends with a cheerleader type and to be excluded at all brings back ALL those painful memories.
- In "The Ornithophobia Diffusion", Sheldon has a fear of birds and a blue jay lands on the apartment windowsill. The blue jay flies in and Sheldon, with the help of Bernadette and Amy, manages to overcome his fear. In the midst of just falling in love with the bird (calling it Lovey Dovey despite not being a dove) he opens the window and the blue jay flies out.
- In the Stephen Hawking episode, Sheldon has to do tasks for Howard, who is helping him with his wheelchair. When Bernadette gets Sheldon to go dress shopping with Howard's mother. When Sheldon points out that her weight makes it hard for her to find a good dress she breaks down saying that she was quite a looker until she ate all the candy she received as gifts from her dates, leading to the start of her weight issues and makes him hold her. For a loud, annoying Jewish Mother, that really is depressing.
- Howard going to see Bernadette after she finds out that he previously hired prostitutes, had sex with his cousinnote and had a threesome with Raj and a woman dressed as Sailor Moon. The show comes this close to making you think they are about to break up.
- Also a Heartwarming Moment, especially considering what happens afterwards.
- Bernadette also has a small breakdown when she learned Penny knew all about his past and kept silent because she didn't expect them to go past "meeting his mom" or "sex." That must have been really difficult for her, feeling like the whole world was lying to you.
- Everyone's What the Hell, Hero? to Penny after discovering that she has never told Leonard that she loves him. She admits that she does to Amy and Bernadette, but hasn't told Leonard simply because she thinks he'd make a big deal out of it.
- Becomes sadder when you realize that Leonard grew up with an emotionally distant mother who never said it either. Is it any wonder why the poor guy simply wants to be told it every now and again?
- Even worse - another interpretation of that scene is that she doesn't love him. She seems like she's only really saying it because otherwise she'd look like she was just using him for sex.
- Howard's "triumphant" return home from space... only Bernadette's sick, his mother is having an affair with their dentist, Raj is doing friend stuff with Stuart that he used to do with Howard, and Sheldon/Leonard/Amy/Penny are occupied with game night. He's left to spend the evening by himself in a local diner (where the waitress offers him some cheesecake on the house but doesn't stick around for chit-chat)... he's left sadly singing "Rocketman" to himself as the episode ends. To top it off, he caught Bernadette's cold.
- A jerk he sometimes might be, but you can't help feeling sorry for Raj in this situation. It seems funny to outsiders, but selective mutism is real and an awful, awful condition to suffer from.
- Howard's story to Bernadette about how he used to put on a magic show for his mother, and that it would help her forget how lonely she was.
- There's just something so heartbreaking (even if it was part of a genuine heartwarming moment right before) in the scene where Leonard goes back to his apartment to let the news that Penny loves him sink in. It makes it seem like he genuinely didn't believe she did before. You really just want to hug the guy.
- It's a little depressing to hear ALL of the guys admit that they didn't do much "father/son" stuff with their dads when they were younger...
- Sheldon's story about how his "Pop Pop", the only person that ever actually encouraged him to pursue science, died when he was little and the only thing he wanted from Santa for Christmas the following year was his Pop Pop back. His other reason for wanting his Pop Pop back was because he didn't want his Mee-maw to be sad anymore. We very rarely see Sheldon show that level of awareness and empathy towards someone else, making it clear how much he adores his grandmother.
- Amy and Raj bonding over how lonely their lives have been. You just want to hug them both.
- "The Bakersfield Expedition" is a spirit-breaking ordeal for all four guys as Leonard's car was stolen, Sheldon is hit with a Slurpee thrown from a passing car, and they are subject to ridicule at the diner where they finally get to call for help. Even Sheldon is left depressed by the whole thing. The fact that the girls got hooked on comic books while they were gone is a small bright spot in an otherwise depressing episode.
- Lucy running out on her and Raj's date in "The Monster Isolation" and Raj's resulting Heroic BSoD leading to him deciding to completely shut himself off from the rest of humanity. Later when she comes to apologize we find out that she has many of the same issues and anxieties that he does and ran away because she was scared.
- Raj's complete and total heartbreak when Lucy breaks up with him via text message.
- The letter from Howard's dad in "The Closet Reconfiguration", which does nothing but give Howard a Heroic BSoD upon remembering he still had it, and sealed. Even when the rest of the crew come up with a ploy to tell him a plausible message that the letter could've held (since he doesn't want to know what the letter said), he's still holding back tears as each person goes through their scenario.
- The introduction of Arthur Jeffries AKA Professor Proton, the childhood idol of Sheldon who once hosted a science-themed kids show in Texas. While Sheldon still idolizes the man, it's clear to everyone else just what a toll life has taken on the old man, as hosting the show cost him any sort of serious career in science. By the time he first appears on the show, he is ancient and spent, and understandably somewhat bitter that all anyone will remember about him is Professor Proton.
- Sheldon admitting that as a child, he didn't have any friends. He sounds SO vulnerable when he explains how Professor Proton would do science with Sheldon every afternoon.
- Raj during Howard's song to Bernadette when Howard calls her his best friend. Raj is coming off a breakup with Lucy, is watching Howard celebrate all the things Raj doesn't have, and on top of that, hears Howard admit that he's been replaced as his best friend.
- Penny sees Lucy at the restaurant and bugs her to see Raj in person after she dumped him via text/e-mail. Raj is happy to see her again, but she tells him that she's seeing someone else. Now it seems like Raj has SEVERE trust issues... Penny sets him up with another girl and, without any provocation at all, IMMEDIATELY suspects she's already got a boyfriend and accuses her of lying about it when she says she doesn't. This guy needs a break SOON.
- Although it's played for the gag, the scene where Amy imagines her life if she never met Sheldon, showing her sitting completely alone in her apartment, celebrating her own birthday with a tiny cupcake. Then her breaking into tears while halfway through singing herself happy birthday, is really quite heartbreaking. It definitely hammers in the fact that before she met him, she had no one whatsoever who cared about her.
- It's more heartbreaking when you realize this is a very sad case of Truth in Television. A lot of people like Amy probably DID spend birthdays all alone unwillingly and Amy was fortunate enough to find people to free her from her loneliness. Spending your own birthday all alone, with only a tiny cupcake and no one to even wish you happy birthday, leaving you in tears...
- Stuart imagining that he's cool and dating Penny starts off quite funny, until the scene cuts back to reality showing him sitting alone in a near empty restaurant, the look on his face when he zooms back and realises how alone he is, is really quite sad.
- "The Proton Transmogrification" is all about the death of Arthur Jeffries, A.K.A, Professor Proton. Sheldon at first appears to take the news quite well, but then he has a breakdown and locks himself in his room. He dreams that Arthur visits him, and there Sheldon explains that since his father and grandfather died when he was young, with Professor Proton dead, all the men he looked up to are now gone. Arthur gives Sheldon one last piece of advice: to appreciate his friends. When Sheldon wakes up and sees Leonard, the first thing he does is give him a heartfelt hug, an unusually emotional move from the typically detached Sheldon.
- Just when you think life couldn't treat Stuart any worse, his comic book store burns down. Stuart being the Woobie is just not funny anymore.
- Sheldon's mental breakdown that life is changing so fast and it needs to stop. He takes a trip on a train to let him straighten his ideas.
- Amy has an emotional breakdown at the end of the episode once it finally sinks in that Sheldon is gone.
- The season premiere is somber to say the least. Leonard and Penny are finally married, but their relationship may never be the same with all the tension related to Leonard's Season 8 finale admission (AND the fact that she's a co-worker). On top of that, Sheldon and Amy seem to be officially broken up and Sheldon is having trouble dealing with it...
- Becomes a happy Tear Jerker as Leonard's admission allows Penny and Leonard to resolve there longterm insecurity with each other in the following episode.
- After Leonard moves in with Penny, Sheldon is worried that he is going to see less and less of Leonard and lists all the reasons why they would have dinner with each other on special occasions. The first two reasons are funny only for it to end with him claiming Amy will marry someone else, someone better than Sheldon. It seems the idea he may have permanently lost Amy has finally sunk in, and it's hit so hard he'll actually resort to self-criticism. Sheldon has such a sad look on his face that he really sells it.
- After Sheldon convinces himself to go to propose to Amy, he walks to her apartment and sees her returning from a date and receiving a kiss. He doesn't say a word, just puts the ring back in his pocket and walks away. It's a credit to Jim Parsons' acting ability that you can tell how utterly crushed Sheldon is without speaking.
- The depth of Sheldon's feelings really hits Leonard and Penny hard after they find out about his plan to propose. When Sheldon snaps at Penny "I SAID I'M FINE", it looks like she's trying not to cry.
- In The Mystery Date Observation, Amy finds out she is dating a Sheldon Cooper fanboy. While the laugh track is quite amused, the fact that all the things he keeps raving about were things that involved Sheldon being a selfish Manchild towards her gets kind of depressing.
- In The Platonic Permutation so they don't waste the tickets, Sheldon and Amy decide to go to the Aquarium café Thanksgiving Dinner as friends. Though the food proves to be awful, the two have a fun time together. So much so, that Amy begins to remember why she wanted to date Sheldon in the first place and begins to miss their interactions. That night, she calls him and asks if they can get back together. Sheldon, still having problems with their breakup and getting over her, turns her down stating they need to stay friends for the moment. Amy quietly accepts this, while looking heartbroken. Worse still, it's the end of the episode, so we're just left with a look at Amy's disappointed face.
- While The Birthday Synchronicity is otherwise a very heartwarming episode with Howard and Bernadette's daughter being born, Howard briefly laments that Mrs. Wolowitz would have made an amazing grandma if she was still alive.
- In "The Emotion Detection Automation," Sheldon is shown to be deeply upset by the fact that he has such a hard time reading other people's emotions, and that he genuinely dislikes his (apparent) Lack of Empathy. However, as Amy points out, the mere fact that he's upset by this shows how far he's come since earlier seasons.
- After nine seasons, we finally learn why Sheldon always knocks three times before he enters a room: when he was a kid, he accidentally walked in on his father having an affair.
- When Georgie reveals to Leonard (and the audience) that his mom is most proud of Sheldon out of all her children, even after all of Georgie's sacrifices and when he is also a successful businessman.
- Sheldon and Georgie's animosity and reconciliation. It turns out that Georgie had to grow up far too fast after their father died to take care of the rest of the family while Sheldon was studying abroad, and he kept the fact that they (especially their mother) were suffering from Sheldon to protect him.
- A deleted scene has Sheldon and Amy receive a wedding present from a deceased Stephen Hawking. Leonard is on the verge of tears when he comments that Hawking must've sent it shortly before he died. Given what an iconic and revolutionary figure Hawking is in science, we can only imagine how hard the guys must've taken the news of his passing.
- In her vows, Amy admits that while she dreamed of her wedding day as a child, she eventually stopped... because she thought that day would never come. Thank God times have changed.
- A minor, but still profound, one happens between Sheldon and his mom before the wedding; they both wish his dad could be there.
- The Rousing Speech from Sheldon's father on the VHS tape. It was exactly what Sheldon needed to hear to get him out of his depressed funk and back on track.
Sheldon: Thanks, Dad. We're gonna give 'em hell.
- Leonard realizing that his horrible, emotionally neglectful mother will never change, but nonetheless, he does still love her... so the best thing he can do for himself is forgive her, even though she does not deserve it and doesn't realize she's ever done anything wrong to him. It's a depressing reality for many people with abusive families that their abusers will probably never apologize, or even realize they did anything wrong, and sometimes, the only way to really get closure is to let go of your anger towards them and move on.
- It's worth pointing out in that moment she did realize how much she's wronged her son, and for the first time was completely speechless and had no snarky remark. So there's that, at least.
- Amy crying in the bathroom because of how she looks in photographs. While she's been upset before, this is the only time in the show where she sobs openly.
- Sheldon's Nobel acceptance speech is a happy tearjerker, when Sheldon finally casts his ego aside to acknowledge his friends and how much they've helped him. All six of them look ready to burst into tears.
- What's the last scene of the entire series? The entire gang happily eating takeaway, all while a guitar version of the theme plays.
♫ Our whole universe was in a hot, dense state
Then nearly fourteen billion years ago expansion started, wait
The earth began to cool, the autotrophs began to drool
Neanderthals developed tools
We built a wall, we built the pyramids
Math, science, history, unraveling the mysteries
That all started with the big bang. ♫