Ok, so you hand in a colouring sheet (to your teacher) that's supposed to have the sea, sun, sky and island coloured in. You colour in the island, sky and sun but leave the sea white. You hand it in.

Teacher: Why isn't the sea coloured?
You respond with: Because the sea is clear. It's only blue because the sky reflects off it. I though we were supposed to be the ones learning not teaching!
Teacher: ...