Today (December 25, 1642) is Issac Newton's birthday, a person who can be demonstrated to have existed.

So with your feet planted firmly on the ground as described by his theories on gravity, and with your eyes to the planets and stars that move precisely by the laws Newton described with his book Philosophiæ Naturalis Principia Mathematica that finally resolved Kepler's laws of motion, knowing that rainbows are created by mixtures of light and not promises of a deity to not flood the Earth (again) yet are still stunning, remember who it was that advanced science on this day, and be thankful for scientific endeavour.