It all depends on what you want out of life. If you want to stay in one area and go as far as possible, yes I would follow this advice. You'll probably be more

It all depends on what you want out of life. If you want to stay in one area and go as far as possible, yes I would follow this advice. You'll probably be more "successful" overall. But I was never that type of person; I've always been pulled in several directions. So I've sequentially focused on each of those, and made shorter careers out of each. Of course I haven't gotten as far in each, because there just isn't time. And I've struggled harder, stepping into new areas and being a beginner over and over. But it can't help but make you stronger and more of a person overall, or at least I like to tell myself that. Every minute Willard sits in that room he gets weaker, while every minute Charlie squats in the bush he gets stronger! And there still end up being weird little synergies sometimes, where something unrelated nonetheless applies in an unexpected way, usually on more of a metaphorical or symbolic level, that gives some insight. I should say I've basically still been honoring my 3 or 4 main circles, plural, of competency, i.e. I still pursued things for which I had aptitude and interest, and not totally random ones!