Should you ever want to be truly entertained watching someone build something, you should go watch a crew of Mexicans building pallets. There is a pallet company in southern California, will build any kind of pallet, made to order, ridiculously cheap. As in materials and labor $10- $12 cheaper than we could buy materials.
Year we were out there working bees on the almonds we went to pick up a truckload - (24 ft. flatbed loaded front to rear, 8 ft. high)
I was watching them assemble pallets while they chased our pallets down and loaded the truck and was blown away at how fast the two guys were moving, without really looking like they were moving. Had a jig set up on a turntable, one would grab 3 - 2 x 4 and drop them in, the other would grab all the slats and literally throw them across the jig, then drag his hand across them to spread them nailing as he went. In the meantime the second buy was nailing bottom slats on the previous pallet, and stacking it on the pile.
It took them awhile to get paper work done, pallets found, and truck loaded, (there was about 20 acres of pallets there stacked 30 feet high), so we checked the time on assembly of a pallet, and those 2 guys were turning a pallet out in under a minute. Next time you look at one, with all those slats, all of which have 3 - 4 nails in them, imagine trying to put all of that in a jig, spread the boards, shooting that many nails and pulling it out of the jig in 45 - 50 seconds. Handing it off to your partner, who flipped it, nailed bottom slats on it and stacked it to be carried away and grabbed your 2 x 4s to start over in the same time.