I thought one time, I figured out what the deception could be; the optical illusion. That the Earth is round 'is' the problem.

When joker astronaut goes up in sky, looks out across the land to the horizon from an elevated position. I suspect without math, drawing or fact changing my initial guess. I imagined from a certain point of view, from mon high, to look out over top the surface of a spherical egg shaped planet, from certain places at certain elevations, with a combination of land topography of slope in a certain recline, and the rounded receding lay of the land along an angle, or even slight curved tangent that negates lens curvature in a nullifying ration, you might see what looks like the earth running flat for a really extended distance that does not have the appearance of curvature.
Like being NW and looking out se as the land rises so that the horizon is higher than the point from beneath the camera position on the ground it would in rising follow the warped perspective of appearing to not contain such curve necessary to wrap around in a ball the landscape in proper size to circumference of the World.