> The answer is very simple: productivity + youthful optimism. Culture also plays an important role. In the U.S., work ethics largely trumps work-life balance,

> The answer is very simple: productivity + youthful optimism. Culture also plays an important role. In the U.S., work ethics largely trumps work-life balance, and the threat of being perceived (or seeing oneself) as a slacker spurs you to work long hours or take very few holidays. It also relieves some anxiety, as in, "I work hard, at least they can't take that away". But there is a high price to pay for it, and burnouts or massive regrets later in life are parts of that price.