The conversation between human and AI assistant.
Why do we not feel like sleeping but when we're sleeping we don't feel like waking?
Can you tell me why we don't feel like sleeping sometimes, but then when we're asleep, we don't feel like waking up?
Well, the feeling of sleepiness is often caused by an accumulation of a chemical called adenosine in the brain. When we sleep, this chemical is effectively cleared away, which allows us to feel more awake upon waking up. However, the exact reasons why we sometimes don't feel like sleeping are still not fully understood.