Hand calculation Memes

That moment when you realize some mathematician in 1876 was sitting there with quill and parchment calculating a 39-digit prime number while you struggle to split the dinner bill without an app. The absolute madman was Édouard Lucas, who discovered the Mersenne prime 2 127 -1 (a 39-digit behemoth) using nothing but his brain, paper, and probably an unhealthy obsession with numbers. Meanwhile, I need a calculator to figure out if I can afford guacamole with my burrito. Evolution clearly peaked in the 19th century.