When I was walking on the sidewalk with Michael after the rain at night, I was looking at my feet. We came upon a puddle covering a driveway such that my visual field was only sidewalk and puddle.
The puddle was so still that I could see the image of trees reflected in the water in perfect clarity.
Immediately, my imagination got the better of my reason and filled in the rest of the environment: a narrow path cutting through a vast, still body of water.
I became self-conscious being on such a narrow sidewalk with water at both sides and stumbled. The next moment, it became clear that it was simply the ground.