I see so many people dragging through life not because they’re physically exhausted, but because their nervous system is fried. The culprit? Inability to control your own thinking. When should you think hard? Only when you’re in the middle of something that demands it. When should you shut it off? When the thing hasn’t happened yet, when it’s happened but you’ve scheduled a time to address it, when it’s over and you’ve already learned from it, or when it’s unchangeable. We waste so much mental power on premature worry, off-schedule rumination, pointless replay, and hopeless obsession—that’s what I call "churn thinking," not real thinking. These loops don’t produce results; they just burn you out, and a good night’s sleep can’t fix that kind of exhaustion. The trick is simple: give each problem its own appointment slot, and when the slot’s over, walk away. If you can’t stop, ask yourself: Is this thought useful right now? If not, drop it. I used to be stuck in this trap myself, and learning to compartmentalize my thinking didn’t just save my energy—it gave me back my life. Start today: guard your mental time like it’s precious, because it is.