The Internet!
WP most of all.
There is something to say for people in person, and much against the idea.
I would think age and interest define it. The young need humans to become one, to learn the, "How do I get by on this planet?"
Most older people prefer less social contact, and get good at filtering out the masses around, shopping, traffic, work, they gravitate to small and comfortable social/emotional support networks.
I am a little different than most, I have strong interests, read what the world has published on the subject, and though I know their work, I have never met any of the other people with an interest in the same field. What contact I have, internet, is around the subject, not ourselves as persons.
It is a world of ideas, parts of humans, and best left that way.
In person, a person is their history, family, economics, health, and a thousand points of view. Human friends tend to match these traits.
Not only do I lack the common traits, I am not like others of my area, I am well read, traveled, have a different world view, and I have very strong interests in a few subjects. No one is like me.
On WP I find people not like me, that have some of the same intense questions, the same "other universe" life experinces, and on these points we do have matching traits, perhaps just one, but it means more to me than a thousand life long friends who I have little in common with.
Young people seem to have grown knowing about autism, I was one of a kind, just weird, till discovering WP at 60. I had heard of it, that low public perception, seen Rainman, but had no identity with it, till I came here and learned the many flavors of thought.
The Internet opened the world to me, I sell online, there I do not have any of the people problems I have had all my life, on the Internet they act normal, and are just good customers, in person, it does not work like that.
On the Internet I find people who share my interests, and we work together to expand our knowledge.
On WP I find a shared Neurology that while different, has a sameness, this is my planet. It is not just me, you are all weird! Even the NT's who come here are mostly just good customers.
So the Internet has given me a Neurological world of millions, that beats being the only one.
It has given me access to world business on an equal footing, more than equal, for my skills and the Internet match well.
It has given me contact with interest groups, often the leading thinkers in the field. I can find the latest research on subjects that are unknown anywhere near me.
It is the magic box that tells me how to, and where to buy supplies that just a few years ago, I would have had to spend years finding.
I was mostly repelled by people, had said my only friends were writers, mostly long dead, and now I find I like some parts of some people.
Let us not ruin a good thing by dragging along bodies, and the baggage that goes with them.
This idea exchange works.
As much as the Internet and WP has meant to me, the thought of meetups, seeing the whole of others, repels me.
I have limited time and energy for dealing with people in the flesh. I will continue doing it when I want, for my own reasons, and very limited.
I agree with Ryn, I like to be the stranger who shows up, dines alone, gets through a limited interaction, tips well and leaves. I like Sushi, for they barely speak English, and see all westerners as strange. For an hour, I fit in.