Barnaby is right. It’s a question of taking a little risk, approaching people and making friends. I think the key is to reach out and talk to people.
Having grown up in Europe and other parts of the world because dad’s work moved us frequently, I can say that America is one the most puritan of all cultures. We want “black and white” moral clarity. In America, you have to believe in God, any God; but you must believe in God.
We are polite and friendly but we don’t feel comfortable making “friends” with people who don’t belong to our same group (church, work, etc..). I think that’s because America is a big country and we self-segregate into neighborhoods. For example, people who are solidly middle class would live in Carmel Mountain Ranch. People who think of themselves as upper middle want to live in Carmel Valley. We are isolated in our cars and don’t get a chance to bump into others. I think it’s so dull to live in cookie cutter houses and talk to cookie cutter people.
If you want to make friends of all kinds, New York City is the place to be.