Forget What You've Learned from Your Art Teachers, Even if I'm One of Them

Now there's a statement: a teacher telling you to ignore your teachers.

Oh, the hubris.

Understand though, it doesn't come out of disrespect for my colleagues, but from an aversion to a word that I believe to be the ultimate creativity-killer:

Should.

As in,

You should always paint from dark to light.
You should get proportions right before going further.
You should have known better.

You should, you should., you should

AAAAAHHH!

Where's the inspiration in any of this?
Where's the fun?