When I was 3 or 4 I had this toy airplane. It was a Fisher Price type model of one of the small 2 person aircraft like those made by Piper and Cessna. It rolled around and the propeller would turn. So one day I had left it on the coffee table and I came out of my grandparents bedroom and the propeller started turning and it rolled forward off the table and dropped to the floor.
I never forgot that moment. Those few seconds are part of what has shaped my sense of wonder. It might have been a visit from a departed relative, or an angel playing with me.