Here is one very rational smart man explaining things. You can get a better idea from the animations of tesseract shadows or projections from 4D to 2D.
http://www.youtube.com/watch?v=Y9KT4...eature=related
And here for an animation.
http://www.youtube.com/watch?v=5xN4DxdiFrs
This is my pathetic contribution to show how we all live on the 'surface' of 4D space.
Bert