You're drawing up a storm, in a crosshatching groove, and suddenly the whole thing comes down on you. It happens to experienced sketchers as well as novices. Someone can knock your arm, or a passing truck can hit a pothole, or maybe a turnip falls from the sky and bops you on the melon. Hey, don't think it can't happen. One day last September--but I digress. Proper attention to drawing construction is what will prevent this tragedy from occurring. Add too much hatching to a flimsy structure, and you're just begging for trouble. Also, here's a tip unrelated to art: don't wear black pants in a house populated by cats. Within an hour or so, you'll look like a Afghan yak herder. Well, your pants will. I don't mean your face will get all brown and leathery. That would be silly.
But it would be fun to live in a yurt, I think. Or just to say you lived in a yurt.