As a child I was fascinated by the way a moonbeam on water seemed to move with us as we drove along a shore at night. If we sped up, it sped up. If we stopped, it stopped. Clearly the beam of light was connected to us if not to me.
This became a thought experiment for me and as I matured I realized that it was not just me who had a connection to light beams on water. Logically I knew that somebody else down the shore sees the same thing and that the beam moves with them just as it moved with me. Clearly there are not more moon beams. In fact there are no moonbeams at all. The lake is flooded with light and we see a beam because our eyes are a set distance apart and the light of the moon is in line with these sensors when we see it. The moonbeam is real to us but is an artifact of our measuring tools in that it does not reflect reality outside of personal experience. We don't pick up the light that isn't in line with our eyes. The moon beam is in our heads and is the result of our sensing system: our eyes and their location on our faces.
The moonbeam holds an intimate place in our narratives and poetry but this intimacy is based on self focus as a sort of narcissism. It is a case of believing what we see. But believing, knowing, and understanding aren't always related. Seeing may be believing but that doesn't mean it is true. There is more to this world than meets the eye.
For a bit more on these musing look at my Thoughts and Ideas section on reflected light.