Why Do They Do the Things They Do?

There are many things I don't understand about one-year olds. Here are a few of them:

When they're pinching you and you ask them to please stop, why do they cry?

Why do they put everything (and I do mean everything) in their mouths? For instance, one of the mamas in my Due Date Club on Mothering said her son ate peacock poop at the zoo. Why would a person do this?

How is it that they're so easily distracted that wailing and gnashing of teeth turns into smiling and chattering with a simple, "Look, there's a truck!"

Why would they rather smear snot over their entire face, including in their eyes, then let you take five seconds and wipe their nose with a tissue?

Why do they continue to do something that either hurts or clearly isn't working, like trying to close a lid on their own hand? Isn't that the definition of insanity?

Ah, well. I'm sure they're wondering what the hell we're doing most of the time, too.