Yes, the electricity flows on the outside of wire, now add that knowledge to a circuit, and you see that the electricity flows in between the wires. kinda an oval, encompassing both wires.

We are pretty sure that it is resistance that causes light bulbs and heaters to glow. At least we can measure it as ohms. But, what really is that? Why is some material ohmic, and some material non-conductive, and other material super-conductive? That last one is really weird if it is indeed electrons (as particles) running through there.