wouldn't know (something) if (one) fell over one
(redirected from wouldn't know if you fell over one)wouldn't know (something) if (one) fell over one
Is too oblivious or ignorant to realize or recognize a very obvious thing. You're no expert. You wouldn't know a Rembrandt if you fell over one. Tim's not much of a scout. He wouldn't know a promising pitcher if he fell over one.