If you can do that, that's amazing. Unfortunately many contractors fall into the "if I don't work I'm losing money" mentality and never stop. Then they start converting everything to how many days it cost them to earn and try to never spend money. I've seen it so many times and it's so unhealthy. Strangely it seems to mostly affect people who do get stupid-high rates.
The most absurd case was a contractor guy in a big corp at lunch with employees from the same team - he was pulling 3x our employee rate equivalent and complaining how he can't afford to take any days off or he'd be "losing" his daily rate.