Both Things Are True at Once
When you tell a physician you are tired, foggy, and not recovering the way you used to, a standard physical measures a familiar set of markers — a metabolic panel, cholesterol, thyroid, a blood count, and usually a single morning cortisol reading. That panel is good at one job: ruling out disease. It is largely blind to the biological drivers of fatigue and broken sleep in a healthy, high-functioning man. So the results land inside the reference ranges, you are told everything looks fine, and the actual cause of how you feel is never tested.
Normal labs do not mean nothing is wrong. They usually mean no one has measured the right layer yet. That is the whole premise here: normal is where we start looking, not where we stop.