Draw a blank
Nicola: What was the name of America's first president?
JoJo: I can't believe you don't remember that.
Come on!
Nicola:I know. I know
I've completely drawn a blank.
She could not remember that George Washington was America's first president
Because she 'drew a blank'.
It's another of saying "I can't remember" something. There's another meaning too. If you're looking for something, but can't find it, then you 'draw a blank'.
I searched among the books and drew a blank.
