- In "The Big Bran Hypothesis", Penny trusts the guys enough to give them a spare set of keys for her apartment since she's having some furniture delivered and might not be home when it arrives. This turns out to be a bad idea when Sheldon and a reluctant Leonard break in at night while she's asleep to clean up, because Sheldon's such a Neat Freak that he can't handle having a mess so close by and Leonard was unable to talk him out of it. When Penny finds out, she is furious rather than grateful and comes over the next morning to chew them out. Good intentions or not, breaking into someone's house in the middle of the night while they're sleeping is not cool, especially since she still doesn't know Leonard and Sheldon that well yet. Penny demands her key back and tells the guys to stay away from her, and Sheldon's insincere apology only makes her more angry. Fortunately, everything is set right at the end of the episode.
- In "The Luminous Fish Effect", Sheldon insulted his new boss Dr. Gablehauser with his smug attitude, and Sheldon gets fired for it. Sheldon, of course, gets his job back at the end of the episode, but only because his mother slept with Gablehauser.
- In "The Peanut Reaction", Howard fakes an allergic reaction (by pretending to eat a granola bar containing peanuts) to get Leonard out of the apartment in order for Penny to throw Leonard a surprise birthday party. The nurse at the hospital's reception desk refuses to play along, and Howard's Comically Small Bribe doesn't work. Left with no choice, Howard eats the granola bar for real (after Penny promised to introduce him to an easy friend of hers if he succeeds in stalling), but the extra time needed to treat the real allergic reaction causes them to miss the entire party.
- In one episode, Sheldon is called to a small claims traffic court for running a red light. He concocts an elaborate defense based around the fact that he can't confront his accuser—a camera. Naturally the judge refuses to allow his Courtroom Antics (being a main character doesn't get you a huge trial for a trivial case in the real world), and he is locked up in contempt for insulting the judge to his face.
- Played with when Howard loses his security clearance for having accidentally driven the Mars Rover into a ditch during an unauthorized visit after-hours to the rover control room. However, the rover then discovers bona fide evidence for past life on Mars in that ditch as a result which somewhat explains how he managed to regain his clearance and qualify for a trip to the International Space Station. How he managed to keep his job at all after that is another story entirely.
- The episode made it clear there was no evidence he was the one who crashed the Mars Rover. Which also meant he couldn't take credit for the discovery without incriminating himself.
- Sheldon and Leonard's apartment is robbed, Sheldon collects evidence and expects a CSI team to arrive, while the single responding officer simply makes a list of the stolen items and gives them a police report for their insurance company. Breaking and entering and the theft of home electronics aren't high priorities for the police forces of major American cities.
- "The Killer Robot Instability" has several:
- Penny has had enough of Howard's creepy come-ons and tears into him, holding nothing back. Penny had always expressed how much she dislikes Howard as a person and she comes over mainly to visit Leonard and Sheldon, and she's not going to tolerate inappropriate behavior like that for years just because Howard is also part of the main cast.
- Ironically, Penny ends up on the receiving of this trope after she gives Howard her "Reason You Suck" Speech, which causes Howard to fall into depression, skip out on work, and disregard the fact he is needed for a robot battle he and his friends are participating in. This shows that, as true as what Penny said to Howard, even creepy guys like him can be very sensitive, so Leonard forced Penny to swallow her pride and pull Howard out of his funk since she put him in it.
- When Penny does go over to Howard's, he claims he's not affected by her put-downs, only to burst into tears the moment she exits the room. She goes back in to comfort him and listens to his sob stories about girls rejecting him in the past. She attempts to give him advice by saying that if he stops trying so hard, then he'd have better luck with girls, noting that for the first time since she met Howard, she feels like she's talking to a real person and she likes him. Howard thinks Penny is flirting with him and moves in for a kiss, resulting in Penny punching him in the nose. When the guys find out about what happened, Howard has no remorse and merely says that he's halfway to pity-sex. A creep like Howard isn't going to change that quickly and it's not until years later when he gets together with Bernadette that he finally becomes a decent guy (with Penny ironically being the one who introduced them.)
- Penny's car finally broke down, after years of Sheldon telling her to pay attention to her "check engine" light, which was portrayed as just a joke. This is what happens when car maintenance is ignored.
- Penny, a struggling actress who works a minimum wage waitressing job yet also lives alone in an expensive apartment and spends hundreds of dollars a month on expensive clothes and acting lessons...has major credit card debt, is in constant danger of getting her power cut off, and has to mooch food and WiFi off Leonard and Sheldon. In later seasons she gets a high-paying job as a pharmaceutical sales rep and is more financially stable, but still saddled with her debt, since credit card debt usually has interest and people who are bad at managing their money will still struggle financially even if their income increases.
- In one episode, Sheldon tries to discourage his female assistant from a relationship with Leonard by giving her a lecture on the dangers of casual sex, including showing her pictures of STD infected genitals. Naturally she finds this deeply disturbing, and reports him to Human Resources. Also, while Sheldon's there he (with characteristic bluntness) tells the HR rep about his friends' own behavior and misuse of university resources, getting the whole group in serious trouble.
- At a conference, Sheldon approaches accomplished astrophysicist and Nobel Prize winner George Smoot with an offer to collaborate. Predictably he insults Smoot to his face by claiming his career has stalled and makes it clear that he expects to be the lead researcher and get most of the credit. Smoot just stares at him, says "With all due respect, Dr. Cooper, are you on crack?" and walks away.
- Despite their break up, Leonard and Penny still spend time together as friends. However, Leonard begins dating Raj's sister Priya who demands that Leonard end his friendship with Penny. Most people in a relationship won't usually agree with their partner spending that much time with their ex.
- The guys take a trip to Mexico in Richard Feynman's old van, and get a flat tire. While trying to remove the wheel one lug-nut sticks, and they use increasingly elaborate MacGyvering to try to remove it. Eventually they resort to thermite, and predictably set the van on fire.
- Bernadette's friends will tolerate her bad temper and bitchy side because they know she has a kinder, softer side. Her coworkers, however, do not know her as well as her friends do and only see her unpleasant qualities, thus Bernie is widely feared and disliked in her workplace, as shown in season eight.
- Leonard, Sheldon and Howard come up with an idea for a new guidance system and try to patent it through the university. They are stunned to learn that Cal Tech will retain 75% of the ownership, they can't patent it themselves because under their contracts the university owns their ideas, and since Howard is technically a NASA employee he isn't entitled to have any of the profits. These are all fairly standard policies that companies and educational institutions have for patentable ideas their employees come up with.Leonard: So the three of us do all the work and only end up with twenty-five percent?
Patent Lawyer: Dr. Hoftstader, this university has been paying your salaries for over ten years, do you think we do that out of the goodness of our hearts?
Leonard: Well, until you just said that mean thing, kinda...
- In season nine, Raj tries to date two women at the same time. He learns the hard way that it doesn't work, and sure enough he's single again during season 10.
- In season 10, Raj decides to stop taking money from his father and become self-sufficient. In the very next episode, Sheldon goes over Raj's finances and tells him he needs to make serious cutbacks to avoid bankruptcy. Raj works full time, but he has been living far beyond the means of a mid-level academic, with high rent and car payments and many examples of frivolous spending. In the episode following that, he can no longer afford his lavish apartment. As a result, he moves in with Leonard and Penny until he finds a place of his own above Bert's garage.
"What, you guys think you're the first government contractors to miss a deadline? We're still waiting on a giant space laser Reagan ordered to beat the commies."
- In Season 10, the guys get a contract to develop a new guidance system for the military. Sheldon commits to a ridiculous timeline, and after buckling down and working long hours... they realize it's completely impossible. Then they spend an entire episode panicking about telling their military contact, but when they do, he shrugs it off and asks for a revised schedule.
- After a year, Howard, Leonard, and Sheldon finally get the prototype working and are happy to get ready for the next stage. To their shock, the military promptly confiscates the prototype and all their research. When they confront the Colonel about it, he tells them that the next stage, which is applying the guidance system to military technology, involves high-level security clearance that none of them have. As a result, scientists that do have that kind of clearance are going to be replacing them in order to complete the project. All three of them have no choice but to reluctantly accept this.
- After a conversation with Amy and Bernadette about their high school days, Penny realizes that she was a bully growing up. She decides to call up the girls she picked on and apologize for how she treated them. However, many bullied individuals usually aren't willing to forgive the people who picked on them, and reject her apology.
- That same episode also has Leonard reuniting with Jimmy Speckerman, one of his high school bullies, who, like Penny, had no idea he was a bully. Although he apologized to Leonard while drunk and Leonard allows him to stay the night, Jimmy is back to treating Leonard like garbage once he sobers up in the morning. Bottom line: most bullies are unaware that they are assholes and even after being informed, they will often have no remorse for their actions and will continue being bullies into adulthood. note Rather than back down from the bully, Leonard stands up to him. Despite no longer fearing Jimmy, Leonard is still no physical match for him (he tried to shove Jimmy towards the door, but Jimmy barely budged), as Leonard is a short, unathletic nerd while Jimmy is much, much larger than him and no stranger to violence.
- In season 11, Raj finally got fed up with Howard's jokes at his expense and temporarily ended their friendship. Also, Sheldon was hiding a work relationship with Bert until Bert realized what Sheldon was doing and basically kicked him out of his life.
- Just because Penny is a pretty blonde with some acting talent, it doesn't necessarily mean that she will get the successful acting career that she wanted. In fact, she ends up not achieving her goals at all after getting fired from a bad movie and has to give it up to find another career.
- In Season 12, Raj is tired of being alone and asks his father to arrange a marriage for him. His father sets him up with a woman named Anu, and the two get along great, with her proposing to him on their first date. However, Raj spots Anu hugging another man and immediately assumes shes cheating on him, when she tells him he needs to trust her he blurts out How can I trust you, I barely know you!. The next episode, they agree that they were both rushing into marriage with a near stranger for the sake of being married and call off the wedding, but decide to give dating a try since they do still like each other.
- Again in Season 12, Sheldon, being an Insufferable Genius, has managed to alienate even scientists he respects, and as such he has few allies in the scientific community when he is looking to gain favor for a Nobel Prize nomination.
- After Amy explodes at Dr. Pembleton and Dr. Campbell, she and Sheldon are forced to do damage control by the university in order to not lose their chances at winning a Nobel. They also have to apologize to Pembleton and Campbell.
- Leonard's mother comes to visit and is suddenly eager to spend time with him. He later finds out that she's once again using him as a guinea pig for her next book. Leonard finally realizes that his narcissistic mother is never going to change or even make an effort to apologize for how she has treated him since in her mind, she has done nothing wrong. Even though Beverly doesn't deserve Leonard's forgiveness, he decides to forgive her anyway since he is tired of carrying that pain around. Forgiveness is about letting go of your own pain, not letting your abuser off the hook.
- When Anu moves to London for her dream job, Raj is prepared to go to London to stay with her. Howard manages to catch up with him, but first he has to buy a plane ticket for himself to be able to get inside the airport terminal in order to reach Raj and convince him to stay, which he does. It ends with Howard telling Raj that Raj owes him the money he had to spend for said plane ticket.
- When Sheldon and Amy do finally win the Nobel Prize in the series finale, Sheldon is unprepared for all the sudden publicity he gets and nearly has a breakdown.
- In "The Panty Pinata Polarization", Penny refuses to take Sheldon's order at the Cheesecake Factory as revenge for him banishing her from his apartment. Penny has no right to do this, thus Sheldon complains to the manager and Penny is left with no choice to serve him (though she may or may not have tampered with his food in the process.)
- A big one with Sheldon's older brother Georgie. Sheldon is obligated to invite Georgie to his wedding, at their mother's request. They then get into an explanation for why Georgie is resentful of his little brother; after their father died and Sheldon went to college, Georgie had to pick up the pieces of their family and support everyone since their mother had a breakdown and Missy was useless as a teen. Sheldon asserts that Mom would have told him things weren't fine, but Georgie says Mom, like everyone else, was protecting him because he was a fragile genius, and Georgie wouldn't hurt his little brother by venting to him. We see Both Sides Have a Point; Sheldon gets a Jerkass Realization about how he takes Georgie for granted, as he does with everyone else in his life, and he apologizes. In the meantime, Georgie is forced to confront that he should have talked to Sheldon about this years ago because Sheldon is no longer a spoiled child and an adult who knows better. He realizes Sheldon can be mean and oblivious, but he wouldn't hurt his own family on purpose.
Reality Ensues / The Big Bang Theory