You slept eight hours. You had your coffee. And yet, by 10 AM you're already fantasizing about a nap. If this is your daily reality, you're far from alone. Fatigue is one of the most common complaints doctors hear — yet it's also one of the most misunderstood. The assumption is always sleep. But persistent exhaustion is rarely just about how many hours you logged in bed. It's about sleep quality, nutrition, biology, mental load, and habits you may not…