We've all had times that fill us with that horrible feeling of "Why the hell did I do or say that?"

You know, it's that sick feeling you get when remembering an embarrassment and/or humiliation. :(
Let's share those moments; it'll free ya' up from all that stupid guilt. Besides, it'll amuse the rest of us.
I'll start.
When I was fifteen, in 1970, I told a virginal and reticent girlfriend, who was then 17, that I could wait before we would have sex. She got screwed by my buddy the following week-end.