Clay Shirky:

Starting with the Second World War a whole series of things happened--rising GDP per capita, rising educational attainment, rising life expectancy and, critically, a rising number of people who were working five-day work weeks. For the first time, society forced onto an enormous number of its citizens the requirement to manage something they had never had to manage before--free time.

And what did we do with that free time? Well, mostly we spent it watching TV

Transcript here, video here.

Via Daring Fireball and Warren Ellis.