F4TFriday #36 - Je Ne Regrette Rien?

Edith Piaf had no regrets at all. Frank Sinatra on the other hand, had a few.  So, what about you?

Yes, this week we are asking about regrets. So, with that in mind:

What, if any, are your greatest regrets?

Is it something you wish you had or hadn't done?

If you could do it again, how would you do it differently this time?