Control theory is one of those things that permeates large parts of your understanding of the world about you once you've learned about it even a little bit.

I learned that this category of problems existed when I built a simulation of something equivalent to a quadcopter (not that they were A Thing at the time) in a video game prototype I was working on. This is an interestingly hard problem because it has three layers of state-needing-controlling between "be at point X" and "apply this amount of (asymmetric) thrust". Failure modes aren't just flipping over and crashing into the ground — they also can be like continuously orbiting your target rather than reaching it.