From a hole in the ground

I might have been around, but you're not so chaste.
You're quick to put it down, but you still want a taste.
And you're always asking for some sharp reply;
Except when you're asking for a smack in the eye.
You could never hurt me, if that's what you mean.
Between yourself and me, the biggest wall you've ever seen.
I know you're just doing what you think you're supposed to do
You're still young enough to think you have some kind of clue.
Greener than the clover, whiter than the snow:
Pass your little judgements on a world you'll never know.