Not to be confused with an internal monologue. I can't remember ever having monologued at someone. When I feel a strong urge to explain something, usually when I get excited about something sciency in a movie, I imagine myself telling my closest younger sister about it, even when she isn't around and despite knowing that she probably wouldn't be interested. We rarely even talk anymore, but I still do it on occasion.
So I got my monologuing fix without doing something socially unacceptable.