Great talk. I do worry though when I see the Chinese synchronised swimming team. How on earth does balance compete with obsession? I like the idea of 'flow'. Finding something where the edges between work/life blur. If you are doing something really challenging, and really enjoying it... more chance of a win win. I also think there is a degree of 'first world luxury' about it. Feeding the family you want to spend time with comes first.
Retirement is an industrial age concept. A better concept is financial independence. As you gain independence, your 'job' is likely to become less something you have to do and more something you want to do. A random retirement age likely based on when your body runs out of steam is a silly idea.
Some lucky people find flow early on. Though maybe it isn't luck at all?