That last part is key. When i entered my 30s, is when I went from being a loner (I had been a loner all my life, by choice) to being "my calendar is always full

That last part is key. When i entered my 30s, is when I went from being a loner (I had been a loner all my life, by choice) to being "my calendar is always full" social. Mainly because I started mixing table-top board games and role play in the mix. 2 board game nights and one tabletop RP session a week, all with different people, ensure you see a lot of people. Then every time you see those people, they always end up suggesting extra (often unrelated) things, like going to a movies, a party, going for dinner, etc. Makes for one busy (and fun!) life. I do also live smack in the middle of a very densely populated city, right by a primary subway station, so most of my friends live within 15-20 minutes. That doesn't hurt.