I'm an extroverted introvert, lol... if that makes any sense.
I'm fascinated by people, in large part because I am unable to understand them.
I usually sought out the kid sitting by himself, figured he'd have more interesting stuff to talk about, and I wouldn't have to deal with the annoyance of being surrounded by other kids.
My girlfriend is extremely outgoing, but very intuitive to what is going on in my head, making it easy to talk to her, big part of why I love her, I suppose.
When I had a problem talking to people, I'd hop up on a fence, or sit in a tree and talk to them from up there.