If you're working overtime all the time chasing a carrot on a string, you're wasting your life on a tomorrow that will probably never come.

If being in the moment isn't its own reward, that moment only pays off when you get the reward at the end. If you need to put in too many of those moments, no reward justifies it.

If your work isn't playful, all work and no play makes Jack a dull boy.

The book Drive, by Daniel Pink, does a good job of explaining the differences between intrinsic and extrinsic motivations. I recommend the book regardless, but especially if this topic is intriguing to you.