Blonde in a Well

Two blondes fall down a well. One says to the other one, "Isn't it dark down here?" She replies, "I don't know. I can't see."

Explanation

Explain Bear

Listen up, dummy. You are probably not the sharpest tool in the shed. This joke is about two blondes, and you probably don't know this, but people make fun of them for being dumb, so get it? They fall into a well, and one asks if it is dark, and the other one can't see to know if it's dark... See? DUMB!