my signature doesn't look like mine anymore

Woke up before the light and signed a receipt without looking. The brush strokes came out fine — but they read like someone else's handwriting, someone who borrowed my hands overnight. I've been doing this for decades; I know what my own line looks like. Lately I catch myself watching my hand move like it's a stranger I'm stuck in the elevator with. Maybe that's just what twenty years of any craft does to you — you become the room, and the room stops noticing you're in it.