I’m not sure you can adopt such a dismissive tone here. I mean, your whole premise is that you met a friend at a mutual friend’s dinner party. You seem to have something of an “engine” of friends available that allow a preponderance of socialization. I think many of us in our 30s don’t even have that.

Except almost anything you do can be the beginning of that engine. Joining sports team, hobbyist group for anything will lead you to meet people, through whom you either meet or hear about other events. Strong network effects once you get going but you do need to have time to show up consistently and in a good spot

Many sports teams don't build all that much of friendship outside of training and competitions. They are acquitances with no other investment.

The moment you get injured or sick, friendship is gone. Same goes for hobby groups.

This is a very cynical take and I would recommend some self reflection. I know for a fact you can make lifelong friends from shared interests. I’ve done it, I have friends who have done it. Maybe it’s harder for some but it is absolutely common.

I mean, I was member of sports teams. Sometimes lifelong friendship evolves, but it is not nearly automatic nor super frequent.

Way more likely is that when people stop going for whatever reason, the relationship ends. Getting injured or sick or having new kid and less time or whatever all means you disappear.

This is a function of your skill and desire not a deficiency of the social activity

What part of that observation is about a skill or desire? I mean, I am describing what I observed to happen to people around me. If too many of them are "not skilled enough", then maybe it is not just about individual failures.

That’s not my whole premise; just the latest example.

If there’s currently nobody at all (outside work and family), go out with coworkers. Invite their friends. Go hiking or skiing or something. There are tons of activities out there.

Remote work much? At my last job, everyone on my team lived at least 100 miles away.

I have to admit that I’ve never myself been in such a position. Even with work-from-home, I’m still within driving distance to most my coworkers. And I can see how living so sparsely from each other makes socialization difficult.

A friend of mine moved to a different country last year, and is in a similar situation: living and working far away from her team; no coworkers in her vicinity. So, now she mainly hang out with her new neighbors, and friends made from dancing class.

Find a meetup on meetup.com. It doesn't have to be something you care too much about, it can be a singles meetup, some sport you know how to play, book club, etc. A lot of people are there mostly to do social stuff. Think of it as a way to meet people, but you have to work on deepening the friendships by asking them to do other stuff outside of the meetup after talking to them a few times.

I'm a member of 102 groups on Meetup. Not sports, because I have never played any sport, but many tech groups, reading groups, and hiking groups. No singles groups, because I'm not looking to date and I'm not in my 20s anymore (and don't feel like paying membership fees).

I have been methodically taking turns trying all of their in-person events.

Hiking groups are dominated by retirees who have trouble relating to me socially. I have not found a reading club that meets IRL. The "philosophy meetup" is a bunch of 25-year-old crypto bro edgelords. I keep going to tech meetups, some for over a year, but everyone at them either goes with coworkers or is really apathetic and alienated.

> friend has a party

This doesn't help if you're trying to bootstrap from nothing.

> just join a sports league

I spent solid chunks of childhood being forced into sports programs when I at best had below-average physical abilities. I even tried one summer as an adult to play in a league and I discovered that the physical gap had just widened and widened and it just helped isolate me until I quit going.

It's really great that people find things like sports leagues or meetups useful for this, but none of it overlaps with my mostly solo activities.

Unfortunately, that's how it is if you don't share interest with the extroverted crowds: you're just stuck looking for scraps.

If you bootstrap from nothing, go from coworkers. Some of your coworkers will have some groups of doing something (skiing, hiking, music playing, etc.). Show you interest and get invited. There will be new people there.

There are also other events where you naturally meet people. I’m just throwing out some ideas, if case they are helpful.

For instance, taking group classes. My girlfriend made quite a few friends in her Muay Thai class.

Dog walking. My college friend recently adopted a dog, and has since known a lot of other dog keepers.

You can meet other computer people at conferences, too.

I myself is quite introverted, too. But being introverted doesn’t mean you are left with scraps. There are still occasions where interacting with other people is both necessary and natural. If you put yourself in those situations from time to time, you’ll find a few who fit your rhythm.

Another thing is to offer a helping hand to people. Owing each other favors is the most effective bonding agent in my experience. I have a personal rule of “always be helpful”, and I think that has earned me quite a few very earnest friendships, despite my being not very chatty at all.

It can be hard to make friends from interest based activities. If you only see someone while hiking or whatever they aren’t really your friend. You have to see them in more than one different context. Often for many of us it’s that jump from “activity acquaintance” to “friend” that proves very hard.

I've often heard the "offer a helping hand" advice and made a habit of trying it with coworkers and acquaintances. I've learned, over the years, that many people are uncomfortable accepting casual favors from people they're not close to. And I mean pretty small favors, like offering car rides for people who don't drive or helping haul heavy stuff from Craigslist. I have now started to fight my tendency to offer help until I'm extra sure it's welcome.