Hidden inside basically every physical machine that needs precise control, PID loops are running the show. Quadcopters, self-balancing robots, and even the hot end of your 3D printer all use the same simple routines.
Knowing how they work, deep down, and how to set their mystical three parameters is part art and part science, but it's nothing you can't pick up in a quick talk. Nothing explains complex math better than a few hands-on demos, and we'll definitely be tempting the fates here. By the end, you should be confident enough to code up your own PID routines from scratch and get started tuning.