When the person sitting in front of me wants to recline – and can’t because my legs are jammed up against the back of their seat – I always ask them if they can tell me where I should put my legs. In my mind, I’ve purchased the space, not just the seat. If I don’t want to give away that space, that’s my decision.
The first time I ever used calculus was figuring out the best place to put a lead weigh in a Pinewood Derby car for Cub scouts.