Hmm...
Well there was a small thing. In my first week at high school, I was talking to some people but I forget their names. There was this one girl there, and I couldn't remember her name, and something came up in conversation where somebody referenced someone else saying something and I said "Oh yeah, well thats what she said" forgetting her name.
Now, I meant this in its proper usage, but thanks to so many lame "thats what she said" jokes they thought I was trying to be funny, and was too stupid to understand how to structure one of those jokes.
It was really awkward. Might not sound like much in hindsight, but sometimes the smallest social forgetups are the worst.