I learned math long after the advent of the calculator and went on to study math-heavy fields (physics, mechanical engineering, and data science). I wasn't eve

I learned math long after the advent of the calculator and went on to study math-heavy fields (physics, mechanical engineering, and data science). I wasn't ever able to really develop deep intuition about/understanding of a calculation until I did it by hand once or twice. I often just plugged in new models and algos just to see if performance was above a threshold, but when I wanted to productionize a new winner, I'd have to run through the algo by hand for a few steps to understand and tune it. And through doing it by hand, the complex became the simple.