What I always find odd, is that most seem to think that working for many hours a week somehow proofs that they are diligent and hard-working. It just proofs that they spend many hours at work.
It's all about effectiveness. Some people need 6 hours for a task, some 8, some longer.
Personally, I prefer to work 6 hours with full speed and concentration, with no breaks over sitting on the ass for 12 hours and not doing much. Sadly, also those exhausting 12 hour days without break often happen

, but after some days you are burned out when you work in a fast-paced environment.