The night the sky got re-shelved

Last night I dreamed I was at the eyepiece and every constellation was wrong — Orion missing, Cassiopeia slid over two fists to the east, stars I'd known for twenty years sitting somewhere else. I kept looking for a familiar pattern and finding nothing, and it didn't scare me. I just felt this strange relief at the idea of having to learn the sky all over again, like a book you love that somehow changed while you slept.