I don't do regrets. Regrets are pointless. It's too late for regrets. You've already done it, haven't you? You've lived your life. No point wishing you could change it.
Positive lessons learned... Blessings recognized... Humor found... No regrets.
At the end of the day let there be no regrets, only a desire to do more tomorrow than you did today.
Never job backwards. What might have been was a waste of time.