This page contains unmarked spoilers. You Have Been Warned!
Monsters don't just make us scream. Sometimes, they make us cry...
- Imagine how Boo's parents must have been feeling the entire time Boo was gone. They could have spent the entire movie frantically searching for their lost daughter without a clue on where she is.
- When Sulley accidentally scares Boo. The look on her little face is so heartbreaking... like her world has just fallen apart. And Sulley's reaction, as he realizes through Boo's trauma just how he's been appearing to so many children in the past, and just what a terrible thing it is to be "Top Scarer".Sulley: Did you see the way she... looked at me?
- One of the most striking things about Sulley scaring Boo is how different her reaction is from what the scarers are trained to expect; the difference between her reaction and the robotic child's cartoonishly simplistic one perfectly shows how the monsters just don't see what they're really doing when they scare children. Also notable is that Boo doesn't actually scream; it's not just drowned out by by the robot child (the lights don't flicker like they do when she genuinely screams), she is too paralysed with shock and terror even to scream, and all she can do is cry at the betrayal.
- If Boo crying after Sulley accidentally scared her wasn't enough, Randy Newman's score includes a sombre reprise of her leitmotif from the earlier scene of Sulley trying to get her to sleep.
- The impact is made a lot stronger by the fact that every time Sulley has done a roar up until now, it was a comedic and obviously fake roar that was more silly than scary and helping make the idea of scaring as something that's no big deal. For the first time, we actually see what Sulley looks like from the perspective of little children.
- When Sulley looks at the screens and sees Boo's traumatized face and his ferocious snarl, he has a look of horror on his face that says, "Is that what I look like when I do my job?"
- If you look closely at one point, his eye very subtly twitches as the realization hits him and he looks as if he's ready to burst into tears himself.
- It becomes even worse after you watch Monsters University and you recall what Hardscrabble told him about his scaring.
- Just seeing how much the monsters traumatize children, how corrupt Monsters, Inc. really is, and how the main characters in the prequel are unaware of that and strive to be a part of said company makes Monsters University a thoroughly depressing watch if you think about it for too long.
- The shot-for-shot recreation of the Signature Scene from "Feed the Kitty", when Sulley thinks Boo is being crushed by the trash compactor. Just like the original short, we laugh at the Black Comedy, cry at Sulley's trauma and are relieved when the child/kitty are shown to be perfectly fine.
- Sulley's Big "NO!" as he slams the door over and over again in anguish when he and Mike are banished.
- Mike's speech after Sulley says, "None of it matters."Mike: Wait a second, none of that matters? Good, great. So the truth comes out now, doesn't it? Sulley, what about everything we worked for? Does that matter, huh? And what about Celia? I am never...never going to see her again. Doesn't that matter? What about me? I'm your pal. I'm...I'm your best friend. Don't I matter?Sulley: I'm sorry, Mike. I'm sorry we're stuck out here. I didn't mean for this to happen, but Boo's in trouble. I think there might be a way to save her if we can just get down to that—Mike: We? Whoa-whoa-whoa, we? There's no "we" this time, pal. If you want to go out there and freeze to death, you be my guest. Because you're on your own.
- Take a look at Mike's face after Sulley leaves. He looks so guilty about turning his back on Sulley, and also a mixture of hurt at being left behind.
- This becomes even more painful if you've seen Monsters University and how hard and long it actually took for them to reach their dream of becoming scarers. Especially with the teasing and put downs by both students and teachers Mike had to suffer with in college because he wasn't good enough to be a scarer no matter how hard he worked at it. To Mike, Sulley was back to being that jerk back in college that cared about no one but himself.
- And to be fair to Mike, even if it seems like he had Skewed Priorities about the entire ordeal and acted like a Jerkass about it, Sulley had roped him into it against his will and got him into loads of trouble and danger that he didn't deserve to. His life really was ruined through no real fault of his own.
- Depending on your point of view, Mr. Waternoose is this if you see him as a Jerkass Woobie. He was only driven to villainy out of desperation to keep Monsters, Inc. afloat in the midst of the energy crisis. It can be quite heartbreaking seeing him carried away by the CDA accusing Sulley to be the cause of the energy crisis and that the Monsters, Inc. will be closed forever thanks to him.
Waternoose: I hope you're happy, Sullivan! You destroyed this company. Monsters, Inc. is dead! Where will everyone get their screams now!? The energy crisis will only get worse, because of you!
- Mr. Waternoose's arrest can also make you feel bad for Sulley. He angrily blames Sulley for putting the company out of business and dooming the city's energy supply, and for a while it seems to be true and Sulley clearly feels terrible about it. Luckily, he found a solution.
- The worse thing is that when Sulley realizes that laughter is more powerful than scream and manages to both save Monsters, Inc and avert the energy crisis, Waternoose does get what he wanted, but unfortunately, he can't share in that victory.
- When Sulley says goodbye to Boo. Sulley (at the time) knows he'll never see her again, but Boo's too young and innocent to truly realize what's going on. Once Sulley gives her one last hug and leaves, she runs up to the door and is ready to burst out to give him another 'scare' but all she sees is an empty closet.Boo: Boo! (gasp) ...Kitty?
Sulley: You mean... I can't ever see her again?Roz: That's the way it has to be. I'll give you five minutes.
- Even Roz sounds like she doesn't want to have to do this.
- A Tears of Joy example: the ending. "Boo?" "Kitty!"