In the movie Shawshank Redemtion there is the line spoken by Morgan Freeman's character who says, "Just how often do you ever look at a man's shoes?".
People are like that about watching the sky. They might glance now and then but seldom do they they just watch.

Then if something way out of the ordinary happens, they might not be able to process enough information to catagorize it or remember it. Sometimes its as though a person is psychologically blind to the event. They say that the indiginous natives on the beach could not see the Spanish Galleons until their Shaman showed them exactly what to look at.

1970 near the shore of Lake Erie: I was laying down on my back watching the sky several hours before sunset. With my eyes accustomed to an infinity focus I saw something as I turned my head from right to left. It was a bright reflective silver white cigar shape that was almost thread thin at a great distance. What was beyond comprehension was the fact that it crossed the sky from horizon to horizon in about 4 seconds. I was left feeling as if I had not seen what I had just seen since it was impossible to all my prior experiences.

The reason that I could process what I had seen was probably due to the fact I had once seen a bullet or spark travel from from a gun to the target by snapping my head and eyes in the direction of flight with incredible speed.

You hear people say that eye witness testimony is the least reliable evidence. It is strange to say this aloud but we need permission or prior experience to see what is in front of our eyes. What is visible to one person is psychologically invisible to some else beside them. Then a person's reclollection can be skewed by suggestion or social consensus discussions afterward.

Sometimes there could be things so strange right in front of you that if asked, "did you see that?" you would honestly say, "see what?"

In short, your eyes maight see it but your brain did not.