Young Einstein is bouncing on the couch.
His Mother says; "Albert, sit still."
Einstein replies; "It's impossible for anyone to do that!"
His Mother says; "Don't get smart with me young man!"
Einstein says; "It's too late. I've already learned the truth. Everyone on earth is moving hundreds of miles per hour about the center of the earth just because the earth is rotating and we're all moving 18.5 miles per second around the sun and the sun and all of its planets are moving 140 miles per second around the center of the Milky Way. Also, the whole Milky Way is moving 25 miles per second towards the center of the local group of galaxies and the whole local group of galaxies appears to be moving at 370 miles per second towards the constellation Hydra. So, if you want me to sit still, you must also say with respect to what!"
His Mother says; "With respect to me!"
Einstein starts following her around the house at a constant distance and making every motion she does.