A Head Full Of Nickels - A head full of nickels is someone who can't remember anythin

A head full of nickels is someone who can't remember anything and thinks they're the president of nothing.

My brother is a head full of nickels. He told the cops he was the president of the pizza shop.

My mom says my brother is a head full of nickels because he forgot his own birthday.

My friend is a head full of nickels. He tried to pay for a soda with a chicken.