So this is sort of tangential. But I think it is a lot harder to pinpoint firsts than people really imagine, because their is rarely a single cut-off between the world before X and the world after X, instead there is a slow translation as X gets built and you have X' which is close to X but not really X and X" which is even further but still close. We as a culture than create an artificial cut off to say when X really appeared and ignore all the X' that came before it. For example, the Wright brothers. I am not the most knowledgeable person on this subject but even using wikipedia's history of flight page you can see that it starts to get blurrier. Before them there was of course the history of lighter than air flight, and a history of gliders. To make them the first you have to narrow it down to "the first sustained, controlled, powered heavier-than-air manned flight" as the " first successful sustained flight of an unpiloted, engine-driven heavier-than-air craft of substantial size" had happened 7 years prior to them. I think the reason of this is so blurry is that a lot of these "firsts" are people standing on the shoulders of others so they are only making small leaps that then add up to bigger leaps. Because they are making small leaps other people are doing it at the exact same time and it becomes hard to define who did it first. This happens a lot in Math where multiple mathematicians will reach the same point at almost the same time. The best case of this is the question of who "invented" calculus. For decades there was a battle over who got credit and it seems now that everyone just agrees they developed it independently (although the professors I learned this from approved more of how Leibniz got there than Newton). TL;DR - I think this is an impossible question not only because of a lack of historical records but because "invention" or "firsts" is a lot more amorphous than most imagine.
And this just in apparently, The first sustained, controlled, powered heavier-than-air manned flight was performed by John Brown, two years before the Wright Brothers. I am no authority on the Wrights either, but I happened across this story last week. It shows the murkiness of firsts, maybe Bill Smith will be first next year as more information becomes available. Yogurt often makes me wonder how the hell it became a thing that you do. Pretty sure that a person who was close to starving scraped out the milk jug only to discover that there was a way to store milk for a bit longer if it was Yogurt. If there is any primitive technology that I'm totally in awe of it's the bag. The person who first realized they could take their possessions with them in the skin of an animal really changed the whole game. In video games like Civilization you always discover pottery or mineralogy, fuck all that, the bag was a way more fantastic invention. The post also reminded me of this Stevie Wonder song Black Man
My guess, and I literally have no evidence to back this up, is that tattooing began with scars. I would bet that people were self inflicting scars before they were tattooing. I would imagine people admired others peoples scars and that's how it began. Or perhaps it was birthmarks? I agree though, these are interesting things to ponder.