I just realised that I have never seen or used it, neither crude oil of course, but there are more variants of it than this natural mineral that powers a lot of the world.
When I was a kid, for some reason I really wanted coal for Christmas and I was diappointed that only the bad kids got it. My parents decided to mess with me one year by hiding all my actual presents and only putting a piece of coal in my stocking. I was thrilled and thought it was so cool. I have no idea why I thought it was cool, I was a weird kid. My parents gave up on the joke before I even realized that none of the presents under the tree had my name on them. I was entirely happy with the piece of coal.
Ironically, it's become one of my favorite Christmas memories and it's one of few presents I still have as an adult.