I was 23 when I dropped out of university due to lack of money.
I went back at 36. I found it easy to make friends because I am a total idiot, and as it turns out that's kind of congenial.
If you want to go back, you'll find a way. Just make sure you know why you're going and that you have a clear plan. The older you get, the more important it is. If you are only going to have a laugh and make friends - there's nothing wrong with that, but you have to be honest with yourself and make provision for that. If you are going to improve employment prospects, or for pure education - that's fine too, but it's critical that you are competely clear why.