I've been thinking a lot about both fatigue and stamina during my time in maintenance as I have random issues with both. While doing my exercises this morning I came up with a gas tank metaphor that helps me get it straight. Please let me know if this makes sense. Fatigue: You wake up and the needle is below E. Blinking takes effort. No matter how much you try to put in the tank, the needle steadfastly remains on E. Try again tomorrow, maybe the hole in the tank will self-repair over night. Stamina: You wake up, the needle shows there's fuel in the tank but the gauge may or may not be broken. At some point in the day, usually unannounced, you WILL run out of gas. No matter how much was in the tank to start, you're just not getting the mileage you thought you should. Refilling the tank may take an hour (rest, snacks) or it may take over night.