I actually thought about this the other day. I wondered if my friends ever went out alone, most likely not since most of them have girlfriends and seem to spend every day with them.
I don't really go out alone at all, but around 3-4 weeks ago I was feeling pretty lonely and spent the whole week doing things by myself. I went shopping alone (which is so fucking awesome) and brought a whole bunch of shit I needed. I went and played in a local poker tournament all alone (though I bumped into people I knew there). I then went to watch a local cricket game all by myself. I don't do it much, but it was kinda cool. It's good not to rely on others and be able to do things on your own and not need others. I have a lot of friends who most likely would have accompanied me during these things but I wasn't in the mood to organize anything.