I found that trying to solve the Advent of Code (https://adventofcode.com/) - once they were describing a problem where people were doing things, I'd actually model out the people and the stuff they would do. Elves fighting? Awesome, let's abstract that out. They all get stats and attack functions and make decisions. Elves in an assembly line? Cool, make each one take care of their own work.

So much easier conceptually than trying to use the math to abstract it all down.