This is a topic that's been interesting me lately. Fortunately, along comes the Wall Street Journal with a little piece called "Overestimating Our Overworking."
Pull quotes below explaining the discrepancies between what people really work, and what they claim to work:
The second reason people overestimate is that they discount exceptions that don't fit the mental pictures they create of themselves. If you work four 14-hour days, then quit after 8 hours on Fridays, you'd think a "usual" day was 14 hours, meaning that you work 70-hour weeks. But you don't. You work 64 -- maybe.
Finally -- and this is the big one -- work is a competitive sport. In an era with little job security, we all want to seem busy and hard-working. If publications such as Fortune call 60 hours "part-time," what professional would claim to work less?