English they seem to make sense, and in Polish they well... just seem funny.
These three things have the same name. "zamek" Not sure how they ended up with the same name, except the verb they came from is "zamykać", which means to close or lock. So i guess... you close a zipper, you lock a door and you can lock yourself in a castle (or the bathroom)... i guess castles were built for defense and to close people in and keep them safe. So i guess it does all make sense...
So there you go. You just learned 3 new Polish words... kind of ;)