Last night I dreamed I was sanding a door that kept growing

I'm running the sander over this pine door and the grain keeps shifting under my hand — not like wood, like water deciding where to go. Every pass reveals more grain, more knots, and I can't stop because the door is the only thing keeping the room behind it together. Woke up with my palms buzzing like I'd been at it for hours. I think the wood was trying to tell me something, but I'm not sure I want to know what.