I think you hit it on the head, JAM. Some of our high school and college friends are still around (ie. within the state, not necessarily nearby)... but we've just all moved on to different places in our life. When we get together, conversation inevitably shifts to things that happened in (name time period), and it gets old to talk about those things all the time.

Most of our friends now we've met through work, or through dinner parties/cocktail parties that other friends throw. We hang out with our (well, moreso his) old friends sometimes, but they're mostly single and we just don't have much in common.

I'm sure once some start having kids and others don't yet, there will be another big divide...