We know at least three different worlds. These worlds differ in the number of dimensions they are moving in. There is the 1-dimensional world of calculating, of mathematics. It always uses and combines numbers, which all can be symbolized by a line of a certain length. Then there is our 3-dimensional physical world of bodies and energies - it exists on the timeline always only in one moment, in the moment, which we call "now". But in our mind the world is existing at least 4-dimensional. That means, we not only see and realize the "now-moment" in which our body is existing, we can remember past