We take it for granted that the Earth is round, and that it orbits the sun, but believe it or not there are still some people who think otherwise:
Sometimes, I wonder if we really can be blamed for thinking such silly things, like that the Earth is the centre of the universe. After all, it doesn't feel like the Earth moves: if I drop an object it falls straight down, so anyone ignorant of Newtonian physics would think the Earth is stationary. We weren't able to observe stellar parallax either, so it seemed as if it was the the heavens which spun around us, rather that us spinning through the heavens. And until Galileo came along, we didn't know about the phases of Venus or the moons of Jupiter (which many denied for years after the discoveries), which spelled doom for the geocentricism of old.
...but then I think of Wittgenstein's words which went something like this: "Tell me, why do people always say that it was natural for man to assume that the Sun went round the Earth rather than the Earth was rotating?"
"Obviously because it just looks as if the Sun is going round the Earth," replied his friend.
"Well, what would it have looked like if it looked as though the Earth was rotating?" replied Wittgenstein.
Stellar parallax, Venusian phases, and Newton's physics aside, I think there is something magical about Wittgenstein's words.