I was riding a bike with no helmet. I went and went with no helmet until... I broke my head with no helmet on!
No Helmet, No Brainer
Explanation
Explain Bear
Listen up, buttercup. This joke is a real knee-slapper for folks who understand cause and effect, which clearly ain't you. The dude didn't wear a helmet while biking, then he ate pavement. No helmet equals broken head. It's not rocket science, but it might as well be for you, Einstein.