TIL we need sleep because waste products such as adenosine, which make us feel sleepy, build up while we're awake. Without sleep we die from our brain overdosing itself on its "sleeping pills"

Adenosine is a waste product of neurons and it is a potent nervous system depressant which is why if we don't sleep for a long time we hallucinate, start to feel cold, and feel tired. We feel like we're drugged because we kind of are. It also increases sleep pressure. Unlike other areas of the body the brain has no way of flushing out the adenosine unless we sleep which activates the glymphatic system. if we don't sleep the adenosine keeps accumulating and it can kill us in a similar way an od of sleeping pills can.