I hadn’t thought of it like that before but I like this definition. If I am tired then it isn’t laziness! woo hoo!
Seriously though, being tired has room for WIDE interpretation so don’t go taking advantage of that. Keep working until you are legitimately tired, take a break and get back to it. The break might be 15 minutes, maybe 15 days. But whatever length it is, get back to it.
All this however is dependent on you wanting to accomplish something, feeling fulfilled and satisfied in the doing. If you don’t care about that, then don’t worry. Just quit whenever you want and don’t hassle with getting back to it. But don’t be surprised if you end up being seen as not much help to anyone.
Also, don’t be surprised if at the end of your life you feel like you wasted it.