- People changing personalities when they fall in love/personality change being expected:
like, yeah, "being in love" does often show a really different, weird side of you. Some people do get really silly about it. But like, if you fell for a guy who's prickly and doesn't understand romantic gestures, then him being in love with you won't make him a romantic person suddenly. And frankly, if you fell in love with the prickly guy who doesn't understand romance, it's??? weird???? for you to want him to become a different, romantic person.
When people are wild or weird or unconventional, it's v strange if they get together and become docile loving mates, instead of being wild or weird or unconventional together.
- Fixing the "misunderstanding" by appeasing instead of understanding
Okay so I saw one episode of Big Bang Theory where Sheldon had signed up to go to Mars, and his girlfriend who's name I don't remember was mad about that because she, y'know, wanted them to have a life together, and he hadn't even told her he planned to do this. At the end of the episode this problem is solved by Sheldon saying "okay, then I won't go to Mars."
There wasn't ever a moment of Sheldon understanding why his partner was upset, or trying to, or even apologising for not realising that would hurt her. He fixed it! He's not going to Mars! How romantic, everything is better now.
And this is a really common corollary to the Big Contrived Misunderstanding plot. He does something that she misinterprets and now he has to prove he loves her!! Which isn't done by, y'know, actually addressing the problem or trying to understand her feelings, it's a big romantic appeasement instead. And she doesn't apologise for making wild assumptions, she just says "oh! I see that you DO love me!" and that means it's fixed!
Kinda revealing of how these writers think romantic partnerships work.