[meowfly]

My hunch is that all your moving doesn't help. I'm a similar age and it feels impossible to make new friends. Virtually all my current inner circle are friends from ~20 years from High School and College.

It's much easier to lose friends then gain them. So as people marry, have kids, move, keeping the close allyship becomes more difficult.

The kinds of activities most US 30+ adults are open to are relatively small and easily prone to be disrupted. For example, I might invite someone to watch a basketball game, but it will take a fairly long time for that kind of contact to blossom into a strong friendship. Moving just resets everything.

Also consider I would never call up a coworker I might have known for years and invite to something more personal, like a ski vacation. If I was in college, I wouldn't think twice about doing that with someone I didn't even know that well.