Any scene perceived by a normal person, is actually seen independently by each of the two eyes. That is how we accomplish three dimensional vision. Let us speculate for a moment that the signal path to the brain has a slightly different length from the two eyes. If this was the case, then the brain would get the signals from the first eye, and promptly process them and record them into memory. A moment later, the signals would arrive from the other optic nerve. The brain would then receive this signal, and immediately note that it seems very familiar, being very similar (virtually identical) to an image already in memory. But it wouldn't be a memory from months or years earlier. It would have only been from a memory recorded a fraction of a second earlier! (The brain's memory does not keep "time stamps" on individual memories and has no way of identifying when they first were recorded there. Under normal circumstances, other related experiences that include time-information usually give a person a cue as to when a memory was from.)
