It's really a time tradeoff. I see the first option, as pg and others espouse, as being the typical 20-something right out of college with no life (family life

It's really a time tradeoff. I see the first option, as pg and others espouse, as being the typical 20-something right out of college with no life (family life) and no money. They can afford to spend 100 hours a week on their startup gaining knowledge and experience as fast as they can. Since they have no outside commitments and no huge debts holding them down (other than college), they can do this. The other option is to work a normal job for a decade building experience and knowledge slowly over time and then when you're in your mid-30's start your company. It's a race to gain knowledge and experience and while one way might be preferable to the other, it doesn't mean it can't be done either way.