I was in Mensa back in the day, and on a lark I went to a young single Mensans event.

A woman held them at a bar right on or around DuPont Circle in DC. In fact, I believe she lived above the bar.

That lady was a cryptographer, and had spider in her email address. Possibly NSA or something along those lines. Anyhow, she was like way older than everyone else. A little creepy if ya ask me,...I don't know if I would consider 45 or so "young". Everyone else was under 30, and almost everyone 25 or younger.