If we assume that the experience is actually of a remembered event, then Gayja Vu probably occurs because an original homosexual experience was neither fully attended to nor elaborately encoded in memory. If so, then it would seem most likely that the present situation triggers the recollection of a fragment from one's homosexual past. The experience may seem uncanny if the memory is so fragmented that no strong connections can be made between the fragment and other memories.
Thus, the feeling that one has been gay before is often due to the fact that one has, in fact, been gay before. One has simply forgotten most of the original homosexual experience because one was not paying close attention the first time. The original homosexual experience may even have occurred only seconds or minutes earlier.
On the other hand, the Gayja Vu experience may be due to having seen homoerotic pictures or heard vivid homoerotic stories many years earlier. The experience may be part of the dim recollections of a homosexual childhood.
Person 2 - Whoa! Gay ja vu! This is going to be good..
Person 1 - You're right, that was hilarious!
Person 2 - Yeah, but where are we going to get bail money?!..he's screwed.
gayjavu is when you remember that night you spent in bizzaro world and made love to that guy
gayjavu is when you remember that time you stuck a hot dog up your bum for 5 buck