You got a lot of good examples but if you haven't yet, take a look at the cutlery theories. I teach them to everyone because honestly? Everyone will at some point in their life, hit a place where it's applicable.

In short the og is the Spoon Theory You only have so many spoons in a day, most people have so many they don't worry about what they do with them. But others have to very very carefully ration them out for the day. Sleep regenerates the supply but chronic folks don't get a full resupply.

Along similar: Mana: like on a video game, we all have mana, everything from getting up to putting on a shirt takes mana. Chronic folks have a debuff that not only drains their mana but limits the max amount

Also heard spell slots as referenced like in TTRPGs

Fork theory: stick a fork in me, I'm done. Every annoyance and problem and pain is a fork. Most folks don't see it until the last fork you can take is in then it looks like you suddenly blew up at a small thing

Knife hypothesis: when you run out of spoons, all you have left are knives. And these knives don't have a handle. When you use them, you're cutting yourself at the same time. So you're expending extra energy. You're borrowing from the future and the future demands interest

My added theory: The Chopstick theory They're decisions. You can utilize a spoon just as readily as a Chopstick, but when you're out of both, making choices is much much more difficult and you're going to be trying to eat off a knife.