[brianchu]

When you're in school, you tend to become friends with people you're placed together with - people you were placed with in dorms, people who had the same classes as you and with whom you did projects/psets, and people in the same clubs as you. In that sense, many of your friendships are predicated on chance encounters. Most are, as someone pointed out, serendipitous.

If you want to make friends out of people who aren't your colleagues, you need to take actions to ensure your friendships aren't dependent on chance encounters anymore. If you meet someone you think is really interesting, you need to go out of your way and invite them to lunch/dinner/parties/events. This does blur the line between networking and friendships though. Then again, the strongest network is a network of friends.

I also wonder if there's a difference between SF and the Mountain View/Palo Alto/San Jose area. It seems to me like it would be easier to stay connected with people in SF, since you'll often bump into the same people at different parties/events - I know that this has certainly been true in my case whenever I go up to SF. Down south people are spread out and there's a lot less going on in terms of events.