If I show you three face down cards (normal playing cards, so can be either a red or black suit), and tell you that no matter which two you pick, they would be different colors, I have no doubt you'll say I'm being weird (to put it mildly). Well, nature does pretty much the same thing. This is the simplest explanation of why nature is weird. To be more precise, nature does not tell you the two cards will 100% be different, so it is not quite as weird as that example. But it tells you they will be different some quite high percentage none the less. I won't spoil it immediately, see if you can decide for yourself what percentages you think are weird and what aren't. To add an extra pinch of weirdness, nature prevents you from ever checking the third card in this wicked game. But that's just a minor bonus to the main weirdness above.