[Dr_Acula]

Ive got a small analogy that can help comprehend infinity:

Imagine a man of 2 dimensions, he only knows 2, like a drawing on a paper. You pick him up and put hin on a sphere. He starts walking through it, and soon he realizes it has no end. No matter how much or in what direction he walks, he never sees the end of it. While on his piece of paper, he would reach an end after walking a while, that doesn´t happen here. To him, the sphere is infinite. Becuase he only understasnds 2 dimensions, not 3.
Now imagine that instead of 2, the man understood 3 dimensions, and instead of a sphere, you put him in the universe. Just like us, the thing is that we don´t understand all the dimensions of the universe, and therefore in ou uncapable eyes it is interprete as infinite.