^^^ LOL you can't even see to the end of a long enough hallway. It's called perspective, look into it.
Perspective, the same reason why sun rays converge to a single point in the sky.
It is explained quite easily here: https://physics.stackexchange.com/questions/154951/why-do-sunbeams-diverge-even-though-the-sun-is-much-more-than-a-few-kilometers-a