From what I've observed, when people say they spend "X hours a day working" (for some outrageously high X) what they're really talking about is how much time they spend at work, which is not the same thing. These quantitative games are a bit silly. It reminds me of when people brag about how many lines of code they churn out, as if that were a good thing.

There is a real issue, though. Most startups demand an intensity of commitment that is difficult to reconcile with part-time engagement or even, it seems, with so-called work-life balance.