If sleeping without dreaming (as I usually do) is somewhat akin to being dead (at least as far as our experience in a dreamless sleep is concerned), why are we, then, so very feared of death, but do like to sleep so much?
Many young children are frightened of going to sleep. I suspect that philosophers may continue to notice the similarities between sleep and death long after most people. I myself was well into adulthood before I got used to losing consciousness.
However, we all do it an average of at least 365 times every year we are alive, so it at last becomes a well-practiced activity. It's also a restorative necessity.
It does seem like there are at least some people who, by one route or another, eventually come to a place in their lives or their minds where the passage into death is as fearless for them as is the passage into sleep.
Sleeping is something we do naturally since we were born, and everyone around us does it. After we slept we are fit, feel great and ready for an other day.
Death on the other hand comes with the problem that it is not like a time out after that you come back. You are just gone. Every plan you made is unfinished every though you though disappeared.
If you would compare the life of someone who doesn't sleep with that of someone who does, the person with more sleep is happier and a lot more productive. The other one just gets depressed and his brain forces him to sleep sometime.
It is not certain that all men fear death. Plato wrote:
For either it [death] is an annihilation (thus bringing eternal peace from all worries, and therefore not something to be truly afraid of) or a migration to another place to meet souls of famous people such as Hesiod and Homer and heroes like Odysseus.
Interestingly, Stephen Jenkinson poses "Not success. Not growth. Not happiness. The cradle of your love of life ...is death." (here)