I'm not just talking about romances. It seems like when I first start getting to know someone I'll put a lot of energy into making sure we "click". I brush off their flaws because, after all, everyone has them. After several months of hanging out with them on a pretty regular basis, though, insignificant things about them start to irritate me and I feel like I've pretty much gotten to know everything there is to know about them. Its not that I don't like them as a person anymore, it's just that I'm no longer "enthused" and I expect them to hold up their end of the friendship a lot more.