spacing out for a moment or becoming very confused.
if someone was saying something and you misheard them, you could say 'brain cramp' or 'I'm having a brain cramp' to explain how you're confused or explain something idiotic you said.
A stupid ill-advised idea. An idea where there is a small upside with a huge downside.
Such ideas when work are called genius ideas and when they fail are called colossal failures.
Bill Belichick going for it on 4th and 2 on their own 28 against the Colts on 11/15/2009. Patriots up by 6 with 2-08 on the clock.
Belichick goes for it. Patriots are unable to convert. Colts get the ball on NE 28. P Manning throws a touchdown to Reggie Wayne. An extra point later, Patriots lose the game which they lead by 17 points.
True definition of a brain cramp.
A stupid, pehaps embarrassing, mistake; commonly confused with brain-fart (which is an idea).
I had a brain-cramp and for a moment couldn't remember which hand was my right.