Henry David Thoreau:

It is not enough to be industrious; so are the ants. What are you industrious about?

Teddy Wayne:

"We need to hire a 22-22-22," one new-media manager was overheard saying recently, meaning a 22-year-old willing to work 22-hour days for $22,000 a year.

Perhaps the middle figure is an exaggeration, but its bookends certainly aren't.

Kilian Jornet Burgada asks himself:

How much is it worth sacrificing to do what you love?

Cal Newport:

Do less. But do what you do with complete and hard focus. Then when you're done be done, and go enjoy the rest of the day.

David Ferguson:

My advice? Just find the thing you enjoy doing more than anything else, your one true passion, and do it for the rest of your life on nights and weekends when you're exhausted and cranky and just want to go to bed.

It could be anything -- music, writing, drawing, acting, teaching -- it really doesn't matter. All that matters is that once you know what you want to do, you dive in a full 10 percent and spend the other 90 torturing yourself because you know damn well that it's far too late to make a drastic career change, and that you're stuck on this mind-numbing path for the rest of your life.

Is there any other way to live?

Nathaniel Rich:

The deeper you dive, the more you get paid.

Cormac McCarthy:

Anything that doesn't take years of your life and drive you to suicide hardly seems worth doing.

James Lewis:

You've got to keep grinding.

Peter Thiel:

Probably the most extreme form of inequality is between people who are alive and people who are dead.