Why?

Why is it that the toddler who lives in the apartment above us feels that it is completely necessary to run around his/her room, jumping up and down and screaming...at midnight?  

And why is it that his/her parents seem to be cool with this, and in fact seem to enjoy running around and jumping up and down at midnight too?

Why was that same toddler awake at ass o'clock this morning, screaming in the bathroom?  Which is directly above our bathroom?  Which is a mere four steps away from our bed?  

And why are the walls/ceilings/floors here sooooo paperthin that we hear our upstairs neighbors peeing whenever we are near either of our two bathrooms???

Why why why why why?