“Electricity can be dangerous. My nephew tried to stick a penny into a plug. Whoever said a penny doesn’t go far didn’t see him shoot across that floor. I told him he was grounded.” –Tim Allen
Static electricity is often the first exposure to physics beyond gravity that we encounter in our lives. Simply rub a balloon against a piece of fabric, and you can stick it to almost anything (or anyone) you like, possibly to their chagrin.
But the way you probably learned that it happens — rub two materials together, one picks up a positive charge and the other gets a negative charge — is not only a little naive, it turns out not to account for the static electricity effects we observe at all. And oddly enough, we only determined this back in 2011 for the first time, for a physical phenomenon as old as this one!