I just think the body is wired to do it.

I don't think it has anything to do with light, i think it's more based on your "cycle".
I have had most of my lucids during naps, and something i have noticed is that if i nap around 3 or 4 i will wake up quite frequently.
But if i take a nap after 6 or 7 i will most likely sleep till the next day if i am not disturbed.
This could indicate a shift as to where the brain separates a nap from normal sleep, like an internal clock.
But i guess you could trick the brain, but that would involve you turning nocturnal.