A running list of everyday situations where the obvious thing gets ignored, and what to do instead.
Sitting in the left lane at the speed limit while cars stack up behind you isn't holding the line, it's blocking the lane. The left lane is for passing. When someone catches up to you, move right and let them through, even if you think they're speeding. Don't be the T*sla on Autopilot or the W*ymo.
The middle seat is the worst of the three, so it gets both armrests to make up for it. The window seat, boxed in for the flight, controls the shade. The aisle seat gives up the armrests and the shade but gets the legroom and the easiest way out. If you're in the middle, the armrests are yours, but keep your arms inside them and off your neighbors' space. If you don't fit, that's first on the airline for selling seats this tight. But if they won't give you more room, be considerate and buy a second seat. Either way, it isn't your neighbor's space to take.
Form one line for all the courts, not a separate clump in front of each one. The first person in line takes the first court that opens, then the next person, and so on. It works like a line for a busy restroom: you wait at the front, and the next free stall is yours.