It's a good (long) read, and has some valuable insights.<p>That said, I've been living these principles since I was 18 (long story, lots of tears, bring a hanky).<p>I can tell you that anyone can benefit from this.<p>But most simply, if there were one single trait that I think has been key for me; it's been self-discipline. It has paid off all over the place.<p><i>Finishing</i> stuff takes a great deal of what people like to call "grit." There's a <i>ton</i> of unpleasant, boring, hard-to-digest stuff, in delivering a finished product. In many cases, it can be more than half the project.<p>In my experience, not giving up, and powering through the "boring bits,", when, what I wanted to do, was go into a fetal position under my desk, and sob into Mr. Floppy Ear Bunny, has done the trick.<p>It also does wonders for self-image, and self-confidence (which, unfortunately, is often interpreted as "arrogance" -nothing is perfect).<p>I've found that starting the day at 5AM, and with a 5Km walk (which I <i>hate</i>), is useful. Everything after that, is gravy. Real gym rats beat that handily. Many of my friends work out for a couple of hours before getting into work.