Hours-per-week is not the issue. The issue is the tradeoff between productivity-per-week (which is related to, but not identical to, hours-per-week) and how wo

Hours-per-week is not the issue. The issue is the tradeoff between productivity-per-week (which is related to, but not identical to, hours-per-week) and how worthwhile the project is (in terms of what you'll sacrifice to achieve it). So, if you're Jonas Salk working on a vaccine for polio, you're quite right to leave everything else in the dust and save people's lives (being highly worthwhile, sacrifices are made to get peak productivity). If you're working for your ego, or for something ridiculous like letting people share pictures in a new way, or to silence some inner demons, then you may need to be a little more clear-eyed about the costs of your time investment.