So let's take a random graph. You ever wonder what the the exact slope of a random angle is? Well with differentiation you can actually use maths to figure this out.
Normally you would take two points near each other, draw perhaps a line and see how close you can get. But at some point in time mathematicians started wondering if you can actually get the formula for the slope between two points where the two points are actually put over each other. And turns out you can!
This phenomenal discovery let to huge breakthroughs in maths as a whole. Including the discovery of integration. Which is in simple terms the opposite of differentiation. Only this time it's not so much for the slope but the for the entire area of a graph. For if you reverse it you can actually get the exact size of a surface.
I agree with the sentiment. But the case with Germany and Japan wasn't so much Germany overtaking but rather Japan sloping down (Japan's strict working hours/culture probably played a part in this though).
I can walk 13 hours in my bedroom and still be in my bedroom. An insane mind cannot comprehend this.