When I was younger I used to really like the idea of going back in time to change things though since ageing past the teenage years it doesn't bother me so much and I'm generally happy with the hand that life has dealt me. Obviously there are things when I think 'gosh, I wish I hadn't done that' but nothing that keeps me awake at night.
If I had the opportunity to go back in time, I think I'd be tempted to do a Back to the Future II and give myself sports results that I could bet on/lottery numbers so I could be wealthy, but then again apparently a lot of lottery winners aren't anywhere near as happy as they thought they'd be so maybe I'd try to win a sensible amount of money rather that anything stupid.
Things I'd be tempted to do over? My interview at Oxford University which I remember thinking at the time I hadn't done as good as I could've. I'd like another shot at that as I think I stood a better chance of getting in than I did myself credit. Though in all honesty, I've ended up at a top 10 university anyway and love it. Things I'd like to relive? Holidays from my childhood. We never went abroad very often and things were much simpler when my parents were still married and you're young and stupid and on holiday. That might be nice.
I reckon Bleys doesn't want to travel back in time because he's had some mishaps with time travel in the past (or future!)