Exactly this. We slave away most of our lives in day jobs (and yes, I know we work less than 100 years ago), and try to cram actual living into whatever is left. No surprise sleep often gets sacrificed first. I'm constantly guilty of this myself - if I were to sleep the ideal 8hrs a day, that with a day job and commute and eating will leave me something of 4-5 hours of (low-quality) time for doing other things, which is unbearable when you have any kind of passion or self-driven projects going on, and I don't even have kids yet. I know that sleeping more would let me use those 4-5 hours more efficiently, but it's a hard habit to have - sometimes you really need more time, not better time.

And that's a comfortably-living first worlder's perspective. I'm not trying to compare myself to people who do need to work 2 jobs just to get by.