Il faut que je le croie!

Seeing is believing, but there's a major error in that. Your eyes are trained to make up things that you think are supposed to be there. The shading caused by the sun rays wrapping around an old tree. The leaves all moving in unison as the limbs sway in the brisk afternoon breeze. What you don't know, and the scariest part of it, is that your brain generalizes most situations and keeps a photo of how everything was every time before that you saw it. There's thousands of subtle differences that we will never perceive, and for that I must say, it's necessary that I believe it.