@jeffowski
Before I discovered Spoon Theory I used to describe it as a video/game stamina bar:

- You only have so much Stamina,
- Every action uses it but the amount varies,
- Some things "reserve" an amount of the bar, making it unusable ("I'll need to be able to go to the meetup tonight, so I can't do this other thing today"),
- Some things can drain your Stamina, or stop it from replenishing properly (trauma, exertion, stress)