I hope this story is true:
Two young boys walked into a pharmacy one day, picked out a box of tampons and proceeded to the checkout counter.
The man at the counter asked the older boy, «Son, how old are you?»
«Eight» the boy replied.
The man continued, «do you know what these are used for?»
The boy replied, «not exactly, but they aren’t for me … they’re for him. He’s my brother. He’s four. We saw on TV that if you use these, you would be able to swim and ride a bike.»
«Right now, he can’t do either!»
The earliest version I found was on Holly’s Life. She had been sent it by another person.