If you look at the earth, expecting to see roundness, everything will look round to you. The horizon (which is demonstrably Flat) will look curved. You will put your faith in every computer generated image of space that gets produced by NASA Movie Studios. You assume the earth is round, and interpret all physical evidence on the basis of that assumption. When you step back and take a hard look at reality, uninformed by your biases, reality suddenly becomes free, and anything is possible so long as your senses can confirm it.