Yo mama's so stupid, she took a ruler to bed to see how long she slept.
Ruler Measurement
Categories
Explanation
Explain Bear
Listen up, you chucklehead. This joke is all about how dumb yo mama is. She's so boneheaded that she thought she could measure how long she slept with a ruler. Get it? Rulers measure length, not time. You probably thought time was a flat circle, huh?