One uses common sense to get through life in a reasonable manner. The fancy name for it is "Occam's Razor," but it's the part of your brain that assumes that if you can't find your car keys you misplaced them, and that gnomes did not walk off with them. Your child thinks that a noise in the house could be ANYTHING, up to and including the Boogeyman, but eventually we outgrow that, and think along the lines of the cat, or at worst, a burglar.
Okay, maybe the world would be a lot more interesting if there actually were faeries in the bottom of the garden, but believing all this stuff just causes too many problems. Reality is enough of a bitch as it is.
There are so many factors where the Vast World Conspiracy to Conceal the Aliens falls apart at the seams, that it is just not a productive use of valuable time to think along those lines any more.
Space/Science » in reply to That question could be reversed.
Sure, but that doesn't mean anything.