You can't let work be your whole life or it's going to eat you up. Everyone should read how things are done at Joel's company. Joel spolsky knows how to create a responsible work environment that is sustainable that won't burn out engineers. Here is his key advice: 20 hours of your work week you spend on your SE studies + medition/rest/yoga + administrative stuff + meetings. the other 20 hours is on coding. If you're doing more than 40 hours per week, your not sustainable, and you need to do something to change that. Working at a start up is no excuse, not enough runway is no excuse. The only time you should be working more than 40 hours a week is if you own the freakin company or at least 30% of it.