Whats a Brain Fart?
I sometimes thought it was when something completely random comes out of your mouth. Like, if someone asked you "How are you?" and you say "Cow."
When your mind goes blank and you can't recall something.
when your brain stinks
Senior's Moment. Have a listen to this and you'll understand: http://www.youtube.com/watch?v=Xv1tMioGgXI