A simple back-of-the-envelope calculation in health economics:
Assume you live eighty years (365.25 days/year), working 35 of them for 50 weeks a year, 40 hours a week. This means that almost precisely 10% of your life will be spent working.
During Christmas, I'd like to hunt down data to see if this is a realistic calculation for Canada. I'd then like to compute the numbers for other countries, and, more interestingly, historically.
I'd bet that a few centuries ago, people dreamt of 10%.