As if a double rainbow weren't insane enough, photographer Michael Theusner nabbed a photograph of the first ever quadruple rainbow recorded in nature. While the photo only (only?!) looks like a double rainbow, the other two are behind Theusner. If you're skeptical, io9 explains how that makes sense:
How do we know Theusner's not a big fat phony? Because he's taken the above photo while facing towards the Sun....
In brief: Each extra reflection inside a raindrop produces a different rainbow. Each reflection dims the ray a little bit more, such that higher order rainbows not only become progressively fainter and difficult to see, they also switch what side of the sky you see them on (click here for another visual representation and explanation, courtesy of Atmospheric Optics, UK).
So it's not really that inspiring for those of us who weren't there, but it proves that the phenomenon exists. And maybe one day you'll come across a quadruple rainbow and you won't have to wonder what it all means.