The only thing I wish I hadn't done was go to BV. It was SO EXPENSIVE - and I will be paying it off for the next 278197 years. And everything ended so badly at BV with my roommate running off with the boy I loved; my memories of that place are so scarred. I had a great time and I met a few great people, but I wish I had gone to a cheaper place closer to home so I could have lived at home and continued working.
However...had I not gone to BV, my sister wouldn't have gone there either and she wouldn't have met her husband, so I wouldn't have my nieces. And Nick wouldn't have gone there, and he wouldn't have met Hannah and I'd have no Cooper and Channy. And Matt wouldn't have been visiting that weekend and met Lydia, and they wouldn't have gotten married and then divorced, and I wouldn't have been able to say "I told you so" to both of them.
Also, I really like being a Beaver. So there are some good things about BV. But I still wish I had avoided the whole thing.