Quote from Vinny1:
People shouldn't work so many hours. 40 hours a week is more than enough. Ruining your health is not worth the money. Live simple. The best things in life are free.
+3 -- and one should focus on completing the task, not the number of hours. If you give it 40 hours, it will take 40 hours; if you give it as much time as it needs followed by beer at the beach, it will take 20 hours or less.