It doesn't really matter how irrelevant something really is, being one of the first to do it almost always gives you a bit of an ego boost, especially in a social game. I admit to being vulnerable to that feeling, as well. In WoW, for example, I was one of the first on my server to have a Dragon mount and a Mammoth mount. It's kind of embarrassing to look back now and see how proud I was at the time but I'd probably do it again if I had the chance.
Wow makes you feel amazing once you are the first for something. I remember how good i felt hitting Rank 14 in Vanilla and majority of players in the cities would chat and follow you around like you are a celebrity. I also was one of the first to get the Tundra Mammoth and everyone that saw me were saying things like "You are a boss" etc haha