The very first gadget was probably a rock. When one guy saw another guy using the rock for something in particular, he probably tried to do the same. If he got the same result there was a gadget.
So maybe its not so much how the gadget works, although that can be interesting too, it's what we use it for and why that makes the difference. Any soldier from the last 50 years can give you a laundry list of what a P38 is used for. And it didn't even have anything to do with laundry. I had mine right there on my dogtag chain. It was that important. When I saw another soldier using it for something new, I always made a mental note, even a remark just to reinforce the memory. Might come in handy sometime.
My dad taught me how to make a radio using a rock we found in the back yard, a toilet paper roll, and a piece of his hair. It was magic. The gadgets we have nowadays are not quite as magic, but some are really astounding. To me anyways. I am pretty sure its the gadgets that stick us together. Wax on.