What really blew my mind was the first time I actually noticed the moon (and the stars, for that matter) moving across the sky. Or rather, the Earth rotating under the sky. It still gives me a sense of wonder.
For those who’ve never done this: find a good, comfortable viewing position, with some reference object like a tree branch or utility pole near by. Position yourself so the the reference object appears right next to the moon, then be still for a few minutes and watch as the moon moves relative to the stationary object. Also works for stars and planets - anything in the celestial sphere.
