None of you were here when the world/universe was created, so lets just leave that out of the discussion. Ok?
String theory never really did sit right with me. Frankly there are some parts of the big bang that I'm not sure I agree with. But thats neither here nor there.
Ooz nailed it on the ant. Same thing works for any of the first 4 dimensions.
Try thinking of it this way.
Lay a towel across your lap with your knees spread. Makes a nice big 2 dimensional surface. Now put a ladybug or ant on one knee, headed for the other knee > ..........< far away.
Now bring your knees together, so that the bug can crawl from one side to the other. >.<
A wrinkle in time, or space.
When we (as the bug) figure out how to create that wrinkle, we'll have the key to interstellar travel.