This is really what I think about when I'm falling asleep.

Why do the Teenage Mutant Ninja Turtles wear masks?

Think about it.  

Most ninjas wear masks so that they won't be recognized.  The TMNT masks do absolutely nothing to hide their identity.  It's not like you see them walking down the street and think "Huh, look at the Teenage Mutant Turtle.  It's clear he's not a secret ninja because he's not wearing a mask."

It's also not as if they need masks to show that they are ninjas.  They carry nunchucks and katanas for goodness sake.

When I asked Batman, he mentioned that they are never without their masks, which brings up more disturbing questions.  Do they have a Phantom of the Opera thing going on under it?  Are they horribly grotesque under their cheerfully colored stripe of fabric?

And if you say that they have masks so that we can tell them apart, that is racist, my friend.  Racist against anthropomorphic turtles and you don't want to be that way.  How dare you insinuate that all turtles look the same?

I fully admit that my mind works in strange ways.