Working non-stop forever.

Which is basically the truth. Even when you're not getting paid to be doing things for an employer or client you still have the work of living to participate in. Sure, it doesn't always mean that strenuous effort is occurring but if you aren't paying attention and thoughtfully navigating the mundane and more relaxing moments in life you might end up paying for it later with an increase in the other types of work. So, really, you can decide to take a break from the work of life... but be careful that you don't let it crash into the stuff that makes relaxing possible. A yin and yang of sorts, I suppose.