I'll take shot: Space is defined by the matter in it. Outside of space is nothing. (Consider a vacuum. Then take away the vacuum and consider what's left.) So we see all galaxies moving away from each other. The matter that goes with them are creating what we call "space".
And remember, this is astrophysics, so "getting it" may not be all that easy.
And remember, this is astrophysics, so "getting it" may not be all that easy.