I have this problem (sorta).
When I'm asked a question that requires a bit of thought (usually asked by a teacher in class) before you can answer it, I've got a problem that is sort of a mix between rambling
Anyways, The teachers call consider it mubling (I know this because they usually say "You are mumbling, I can't understand you").
The reason I have this problem is because I've got so many ideas going through my head that when I'm asked to explain something in detail, I basically think to myself outloud and people think I'm trying to explain it to them, and they get frustrated because they don't understand what I'm talking about.
I guess that makes me weird.
Oh well, at least I don't think out loud when I'm talking bad about somebody. That would set me up for some bad experiences.