Jobs isn't simply reminding us that money can't buy happiness—he's identifying time as the one resource we *cannot* replenish or negotiate with. While we might earn more money tomorrow, we cannot earn back an hour spent poorly today. What makes this arresting is that he says it as someone who had more money than almost anyone alive, yet still arrived at this conclusion; it suggests he learned it through abundance, not scarcity. When you catch yourself checking email during dinner with someone you love, you're experiencing exactly what he meant—you've chosen to spend the irreplaceable for the replaceable.