That man would forget his head if it wasn't fixed on his shoulders.
Storm says I'd forget my head if it wasn't screwed on.
She needed time to forget her brother's head on a pike.
"I'd forget my own head if it was wasn't held on with bones and skin and things!"
"A smart idea," agreed Chow, whose head injury had been completely forgotten.
"I'd forget my own head if my wife didn't nail it on me every morning."
"And don't forget to stroke your head when you give the order!"
It's a wonder I didn't forget my head down there.
The pain made me forget my aching head for the moment.
Forget my own head if it wasn't nailed on tight.