Ph.D. for a Blonde

Alright, listen up, buttercup. This joke is about a "Blonde" stereotype, meaning they ain't the sharpest tool in the shed. So, the idea of a Blonde getting a Ph.D., which is like, super smarty-pants level, is supposed to be funny 'cause it's unexpected. You wouldn't get it. You are probably a blonde yourself, or have the IQ of a goldfish.