Burned out, hit my limit, and needed to take a break in grad school twice. Once due to contract work (had to pay my bills, so spent a week writing testing code instead of core product), and once due to emotional exhaustion after writing an unaccepted paper (spent a week watching all 7 seasons of ST: Voyager while my ex was at work).<p>Since then (11-12 years now), the work ethic that pushed me through a PhD in 5.5 years left me burnt out after 60-80 hour work weeks at my first gig. Since stopping working for other folks after coming home (except as necessary for pager duty in some cases), I put my spare hours into relationships, family, and personal recreation. With the wife and kids, basically now just family and personal recreation.<p>Unfortunately, my personal recreation tends to look a lot like work (email support, open source projects, ...). Combine that with "working for myself" for the last 21 months, and I've experienced more pain and stress in the process of building a business than I did getting the PhD (solve all the problems, all the time, no academic advisors, no end in sight). I think at this point I've needed to take explicit "I am burned out on this" breaks at least 5 times in the last 21 months.<p>I've been trying to explicitly "not work" in the evenings to cut my own work-driven exhaustion. Trying to do something fun (work on non-work fun software, handle correspondence, play video games, etc.), but at least half my evenings end with starting an overnight "run forever, log failures" set of unittests, or at least updating my daily worklog.