Like one or two others I didn't go to a single-sex school, but in my first few years there it was predominantly female as prior to my joining it had been a girls only school, with boys having an entirely separate building the other end of the grounds. They'd been joined due to money issues quite a few years before I joined, but the year I joined was the first year that there was a boy in every year group, and it wasn't until my third year that there had ever been a head boy. I also spent quite a lot of my time boarding in an all female house, which was strange to say the least. There were so many things I couldn't understand about living there, like the routine, or the openness about monthly things.
Strictly speaking I suppose the house wasn't all female even with the exception of me, the housemaster was male. And I did spend an unusual amount of time talking to him compared to every body else, when I wasn't escaping or chasing down the member of staff I had a major crush on... lol.
Now I'm on an entirely male college course, but there are females around. And god do I feel sorry for them when they walk into our lessons. I have to say that the atmosphere is much more 'me' here though.