Why the distinction changes everything

They have different causes, so they have different answers, and this is why a single list of sleep tips helps nobody in particular.

Short sleep is usually an arithmetic problem about the shape of your day and evening. Broken sleep and difficulty getting off are where the loop in the next lesson lives. Late sleep is often a body clock that is set later than the world you have to get up for, and that has its own treatment. Unrefreshing sleep is the one most likely to be physical, and lesson six is mostly about that.

So before anything else, work out which one you have. If you have two, take the one that costs you most.