The illusion that ruined friendships since 11 years ago.
Do you still see the dress as having the same colors as you first see it, or are the colors changing to you? I always see it as black and blue, and no matter what I do, I can't have my eyeballs see it as white and gold.
But then you would have light bleed around the edges. Unless you are in an extremely dark room, reflection and diffusion would make the curved edges of the dress receive some of that outside light. Yet the floor at the foot of the dress is well lit.
Back to my original conception of things: understanding of lighting and photography makes the white-gold seem impossible.
I do not deny that people can instinctually miss these details... But I am surprised that further analysis doesn't inevitably resolve in these conclusions.