Wow, a thread by Wolfpac that's brings out everyone's serious sides. After six years, the Forums haven't lost the ability to surprise.
No specific moment, I'm afraid. I used to wish I'd gone to my current school from the beginning instead of wasting time at state school, but eventually accepted that I'd be a different person had that happened.
Lately I've been postulating on what would happen if I suddenly woke up and it was six years ago, but I retained the confidence and wisdom I've accumulated over the years. Ah, the things I would have put so much more effort into had I had hindsight.
EDIT: Which doesn't answer the question. I wouldn't want to relive anything as it was. Onwards and upwards!