It's all just nonsense, of course. Pretty nonsense, but still nonsense. The world is made of nonsense.
Madness string 2251
When you're tired all the time and it becomes normal, it becomes harder for you to tell when you're tired, in my experience. You only admit to being tired when you're feeling exhausted, because that's when you can tell it's different. Because surely I can't be tired all the time?