Of course. Most people do it I think. I do it a lot but talk myself out of it because it's pointless and stresses me out. If you find yourself doing this just tell yourself this: Stop it! It doesn't matter now. It's history. I'm not stupid, it was a bad choice but it's done now. Something like that.
They were lessons learned and dwelling on them only makes you feel foolish and insecure.
If someone told you, what mistakes and bad choices they made, you'd tell them, "Don't worry about it. It's O.K." You wouldn't call THEM stupid and keep bringing it up all the time, making them feel like crap! No.
It's funny ya know...we're never as forgiving to ourselves as we are to other people. Stop beating yourself up!

totally know what u mean. i can get so engrossed thinking about something embarassing or stupid that i did 10 years ago, that it still makes me cringe so much i wanna die. its not clever and is totally pointless. doing some hideous form of exercise helps me forget.