I do suspect that allowing people to lie fallow will result in a group of people that cherishes to just lie fallow all the time.

I suspect you may be right. I also suspect it wouldn't be a huge problem.

In fact I'd guess people who'd disappear into a haze of drugs, sleep and sex would probably be a very small minority. Apes like to keep busy, one way and another, and it might be surprising to see what happens if the usual social restrictions around work are relaxed.