curious, what age would that be? it was late college years and then the first few years out of college for me (first time in the workforce at a largish company where i encountered a lot of people), so in the 20-25 year old range. pretty much every friend i currently have is from college or early work days.
that said, i have two significant outliers to that theory: i made one new good friend about five years ago, and i first met my wife when i was probably twice as old as some people on this forum...
they are the only good friends i've made since my mid-20s. sure, i've made other acquaintances over the years who i might meet up with once a year or converse with occasionally on email, but nothing more than that.