I'm sure I've done something absolutely handicapped more recently but nothing really comes to mind right now, so I'll tell this little story.
During a lunch break, a circle of friends and I were talking. The guy next to me decides to be annoying and starts waving his hand in my face while I'm trying to say something. I turn to him, and, while hardly thinking, I blurt out "I WILL forget YOU".
Reflecting back on it, my brain probably couldn't decide between saying "I will cut you" and "forget off".
People made occasional jokes about this for almost a full year later.