Let's say you want to go to see one movie, but all your friends want to see a different one. Or maybe you don't feel like seeing a movie at all, but your friends are going.
Or there's a party on Friday, but you don't feel like going out. Or maybe you just want to stay home and read a book.
There are countless other situations where you might want to do one thing, but social obligations, situations or friends are pulling you to do something else.