Another wonderful piece, Nathan! I am in full concurment here, some of the best friends can come into our lives at any age. The sky is the limit for adults' friend opps--hobby groups, coworkers, community or religious organizations, and even for advanced aged individuals retirement homes(I'm serious as I have heard stories of people in retirement homes becoming best friends or getting married).
Online and social media platforms are also key places. Heck, even writing sites like here or Quora. I've made some of the best friends ever around the world through these sites.
And speaking of which, I consider you a dear Medium friend. I look forward to continuing to connect with you here. If you are ever feeling solitary blues, you know where to find me here lol(or send me a private message if you want to share writing ideas haha)!