Drawing starts with learning to see

Many people look, very few actually see.

This is understandable. How much time do you have every day to pause, and reconsider every single thing in your field of vision?

A stop sign is a red octagon. We were taught that. We "know" that. We know it enough that we don't have to think about it very much at all. We can spend our energy on more important issues. BUT, if you want to DRAW the stop sign, you have to STOP, pause, and really look at it.

You "know" that it has eight equal sides, but that is just the design; how it was made on a flat surface from a viewpoint that was perfectly centered and perpendicular to the sign itself. From your point of view, your unique angle, the stop sign is either slightly or very skewed. One edge looks larger than the other.

Try this with a camera:
Take a picture of something. Next, you move your viewpoint. Left, right, up, down, does not matter; just move and take another picture. Move again and take another picture. When you look at the pictures, the shape and color of the object will be different in each one.