(Lol, I'm the sort of person who just gets that shit without knowing how to properly explain it… here's a simple way: normal tunnels just carve through stuff without being shorter or longer than the thing they're carving through. A non-Euclidean tunnel would be shorter than the length of whatever you're trying to get through, but would be just as long on the inside as a normal tunnel. A tunnel longer than whatever you're trying to get through would be shorter on the inside, but you'd still get to the other side of the thing. Or… even simpler… Doctor Who's T.A.R.D.I.S. is non-Euclidean. The term infundibular also aplies to the T.A.R.D.I.S. [and I'm not going into that right now, lol.])
Shade shrugs. 4th dimensional now?