Who hasn't had a moment when your brain decided to not work?

Me trying to find my glasses. When they are on my face

I do crosswords as a method of keeping my brain sharp, but the number of times I get thrown by questions like.... name the characters in The banana splits or who wrote the poem I wish I'd looked after my teeth ?
Answers I could peel off for fun in conversation, but suddenly stump me trying to think of them for a crossword clue

Hahaha, I hate it when that happens

I once had a moment when slicing bread, where my brain literally said "error: brain fart incoming"

A brain fart?