Became an expert at making fridge cakes. And pasta. Learned to love sainsburys basics. Also learned which cheap wines are poisonous and which are quite nice.
More importantly, I learned to be a lot more independent and fend for myself. And manage my time better. I'm far more confident.
Joined a bunch of clubs and ended up with a few new hobbies, which I've really enjoyed.
Otherwise, I just socialised loads and got very drunk a few times. Learned how to make a fancy dress costume in ten minutes out of random crap lying around my room.
Didn't do anything I majorly regret, which I'm happy about. I'm not really into pulling in clubs or one night stands, so I was never going to turn into a complete wild child.