The "What Was I Thinking of?" Moments

How many "what was i thinking of?" moments do you have in life?
Something that made so much sense at that time (whether you gave it thought or not), but in retrospect makes you crinch and just want to dig a hole and hide your face.
Wrong dresses, wrong make-up. Basically fashion disasters. Plain stupidity. Silly actions you thought cool. Trying to act cool and aloof. Falling for wrong guys. Impulse to do things -- right and wrong. Taking things too seriously for your own good.
The good thing about having such "what was i thinking of?" moments is that you're out of those ridiculous moments?!?