We have an acquaintance who is not the smartest person in the world. This observably true. Also, he has related the following story.
When he was younger he was at a party at somebody's house. The microwave at this house had a defective safety latch allowing it to be turned on while the microwave door was open. As a wacky party stunt, our acquaintance thought it would be funny to stick his head in the microwave and turn it on for a bit. He did so.
This, of course, leads to the question, was he dumb before the microwave, or did the microwave make him dumb? I'm guessing both. There's probably a feedback loop going on.