There are two of you, and they barely know each other. There's the 6 a.m. version. She's clear. She set the intention. Today's the day she hits her protein, gets the workout in, doesn't graze after dinner. She means it. And then there's the 6 p.m. version. Standing in the kitchen, tired in a way that's hard to explain, reaching for the thing she swore off twelve hours ago. And she watches herself do it, almost from the outside, thinking what is wrong with me. I was so sure this morning. Nothing is wrong with you. You're not two different women with two different amounts of discipline. You're one woman whose body ran out of a resource over the course of the day, exactly the way it's built to. Here's the part your doctor won't sit you down and explain. Willpower and decision-making aren't infinite. Every choice you make all day, what to feed the kids, the work email you didn't want to send, the hard conversation, the hundred small ones you don't even notice, pulls from the same tank. By evening that tank is low. This has a name. Researchers call it decision fatigue, and the science behind it is real, not a self-help slogan. Now layer our stage of life on top. When estrogen shifts, blood sugar gets less stable and sleep gets lighter, so the afternoon crash is steeper and the recovery is slower. The 6 p.m. version of you isn't weaker than the morning version. She's running on a near-empty tank that drains faster than it did in your thirties, and then we blame her character for it. So the fix was never "want it more at night." You cannot out-willpower an empty tank. The fix is to stop asking your most depleted self to make your most important decisions. Front-load the day. Hit your protein at breakfast while the tank is full, so your evening body isn't screaming for fast fuel. Decide tonight's dinner this morning, when the 6 a.m. version is in charge, so the 6 p.m. version doesn't have to decide anything at all. Take the hard thing off her plate before she ever gets there.