It wasn't at Apple or anything approaching it, but I had years of similar treatment - expectations of 24/7 availability, continuous last minute, personal service to executives and never-ending crunch time.

I didn't have kids or a mortgage to worry about and I had enough in the bank that I could probably have spent a year or more unemployed without much concern for money.

For me, it was several things.

* Pride in being dependable and capable of delivering on whatever was asked of me.

* A not entirely conscious expectation that I would eventually be rewarded for such sacrifice.

* Genuine enjoyment of much of the work I was doing.

Needless to say, my outlook has changed a bit in the years since, but looking back, I don’t think it was having a child or any other responsibility that did it.

More than anything it’s probably the simple realization that deriving enjoyment from something doesn't negate its cost. Moderation is straightforward for things which are easy to categorize. The difficulty in categorizing ‘enjoyable work’ is implicit.

I think that saying to the effect of ‘find a job you love and never work a day in your life’ is only talking about a certain part of your mind. Your body and all the unconscious and unobvious bits that make up your life are not immune to wear and tear by virtue of your positive perception.

Next would be understanding the diminishing returns and potential negatives of hard work. In short, if you’re going to work hard for someone else, aim high, help that person succeed and see that their success is tied to yours. Being too valuable to someone with low aspirations is career poison.