If you keep your eyes open by force when you sneeze, you may pop an eyeball out.
A male bee's testicles explode when he climaxes. It's good to know so that you can put things into perspective if you think you're ever having a bad day.
I originally read it in one of those fact books but here's the article i read online to double check it. http://seriousfacts.com/when-a-male-honey-bee-climaxes-during-sex-his-testicles-explode-and-he-dies/
i have no idea, what do you need to know?
how to change the wheel on your car in case you get a flat.
You should know how to tie your shoes.