Random bullets of the capital city of a large country shouldn't be this small

I changed doctors recently - partly because the university clinic now charges me money since I'm no longer a student, but also partly because the random doctor they gave me last time turned out to be someone I knew socially (without realising they were a doctor) and that was a little bit odd.

The new doctor I went to (who I picked at random from a list of doctors that bulk bill Medicare) turns out to have one of my students working as his receptionist.

I went to a party hosted by someone in my department recently, and her housemate had invited a friend, who happened to be the twin sister of someone who works with Geekman. At the same party was an American guy who used to read this blog, and has since moved to Australia.

Another party I attended a couple of weeks ago was for a friend who is not and never has been at the university or connected with it. A guy at that party who I had never met before sat in the corner and picked his nose aggressively all night. The next day we went to the house of one of Geekman's colleagues for lunch and the nose-picker was there as well.

At the same lunch was someone who looked kind of familiar, and turned out to have been a colleague of Stellar_Muddle's (who sometimes comments here).

We went to a "games night" run by a colleague of Geekman's a few weeks back, and someone else she had invited was someone I know from the university rock climbing club.

Possible explanations that have occurred to me include the following:

• Maybe this is just what happens if you live in a city for long enough. (We've been here four years now, which is the longest I've lived anywhere since I was a kid.)
• The circles we move in are a lot smaller than the actual size of the city. E.g. mostly we hang out with people who have some connection to the university. That doesn't explain Nosepicker, or the doctor thing, though.
• This city only actually has 30 inhabitants. The government just claims higher figures because otherwise it's too embarrassing. (This explanation has the advantage of also explaining why downtown is always mysteriously empty).