George Friedrich Benhard Riemann invented an interesting idea that explains why we cannot perceive a fourth dimension. Before we had telescopes and spacecraft and other inventions that could tell us our world is round we thought is was flat. People could not see that the world was round. The fourth dimension is curved and because large curved surfaces appear flat to observers living there, we cannot see the fourth dimensional curve.

Also the fact that we ourselves our only three-dimensional means that we cannot by any means perceive four dimensions. Earth is a hypersphere as it has at least four dimensions. We can only see the sphere part of the earth as it is on our three dimensional plane.