In the majority of cases, even with the most cringe producing memories, there will be something positive that was gained from the experience.
It may simply be that the learning was, never to go down that road again, nevertheless it's important not to beat yourself up repeatedly over something you did at a time that isn't now!
Be kinder and more forgiving for past misdemeanours, and enjoy knowing that the direction you choose today may in fact be easier because of the choices you made in the past that you now spend time regretting!
"Never regret anything you have done with a sincere affection, nothing is lost that is born of the heart." - Basil Rathbone
"If we fill our hours with regrets over the failures of yesterday and with worries over the problems of tomorrow, we have no today in which to be thankful." - Anon