Has that ever happened to anyone in real life? I really rather doubt it. If someone drove me insane by being a complete asshat, why exactly would I want to spend more time with that person? And if that jerk is treatly me like crap, why would I even put up with it? How does that change from "moron" to "dreamboat" happen? I just can't see it. It's not practical, it's not realistic, and frankly, it's not pleasant. I cringe when I read about it; I wince when I see it on TV or the big screen. Yes, little kids who have crushes will pick on their crush - but that is a sign of immaturity - they don't know how to express what they're feeling. Why would people want to read/watch/etc a story about other people caught in arrested emotional development? I'm not saying that people who love each other never argue, but what I am saying is that love can't be built on arguments alone. Real passion does not come from detesting someone.
If you have a true story of this sort of situation working, do let me know. Otherwise, I will continue to operate on my educated opinion that this is nothing but a worn-out cliche.
This seemingly out-of-nowhere rant brought to you by Nick Lowe and a night of reading fanfic. Keeping me away from both in the future... most likely impossible, but viewer discretion is advised.