It’s really damn hard to envision a fourth dimension of space.
I tried! For years. I read Flatland as a kid, and it fried my noodle. In that famous book — a “romance of many dimensions” — the narrator is a square who lives in a 2D world, filled with 2D creatures. He has no idea that a third dimension could even exist, until one day a 3D sphere floats down to visit.
The sphere talks to the square, and tries to explain how the third dimension works. But the square has absolutely no mental model for grasping such a concept.