Talking about yourself is part of the process of meeting new people. It's how you "sell" yourself to the world. The world knows they're watching a commercial, they just accept it hoping the commercial is short, and possibly entertaining.
I used to like meeting new people, even though I've always been lousy at keeping in touch. My best friend hears that a lot at her workplace: "If she's your best friend, how come we never see her?!"
Nowadays I just got tired of the process of sharing things about myself. Things I like, things I don't like, things I've done, things I want to do, what's the point? Most of the time people only pretend to listen to you. Nodding is some sort of metronome for keeping the pace with their unspoken thoughts.
I also got tired of people saying the same things, acting the same way, complaining about the same factors, yet making no changes, unable or unwilling to come up with a plan to shift things around, unable to come up with original lies, at least.
New faces that come with old lines. If you let your guard down, people act like a virus; they creep in, slow you down and take advantage. They're exploiting your weakness while delivering a lethal cocktail of drama, self-pity (or over-confidence) and half-ass friendship.
They're not really interested in being your friends, they just need as many people as possible reassuring them of their own awesomeness.
And all this nightmare for the prospect of a couple minutes' copulation? No wonder people often go for one night stands. "A little less conversation, a little more action, please."