Philosophically, I have problems with the quote. It's supposed to come from R.A.H's author avatar / ubermensch Lazarus Long. Yes, the superman who can do no wrong and is immortal to boot can well have that attitude. For us mere mortals who must live in, depend on and support a community of other mere mortals specialisation is the way to go. We all just have to specialise in different things.
Well you might be right. But its not in my case. Life
made me learn how to do a lot of things. I can play piano, write a short novel, design a magazine, write an article or press release, build a PC from parts, shoot with a rifle, make annual marketing plan, cook myself a meal, write a 100-page computer game concept, clean the house, lead a team of 10 people, and several other things. Except cooking, cleaning and playing piano, I did these things on a level that's acceptable for major companies in Croatia in their field, so I would say I mastered them on acceptable levels. I lack surival skills that R.A.H. pointed out (never had the chance to hunt game or pilot anything), but being profficient in several dozen things is certainly not impossible. And i'm 32.
At the same time, some people were probably working on the same job description for 10 years. But that doesn't mean they are more profficient, because the more
related things you do, the more your profficiency grows. And faster.
Matter of fact, I'm probably one of the top 5 people in Croatia to have if you want to be 100% sure that anything that goes into the press comes out exactly as you wanted (DTP finish overseeing), and I'm talking difficult stuff like spot color gradients, targeted plastification and DVD covers. At the same time, most designers that vastly suprass me in creativity and skill.
Actually that's a good example. If I get the best designer in Croatia for a DVD cover, he'll make a kick-ass design. But I'll be the one to supply him with headlines, be the lector and corrector for the same text, help him work the spot colors, bid for the best price for printing the DVDs, sign the contracts, add the transparency layers, write down the technical details to the printing company, check the PDF for curves, layers and typos, upload the file to an FTP server and finally go check and sign the master before mass production begins. And that's just one of the 10 things I'm fairly confident I could do for any company in the world.
OR
I could hire 10 more people to do all the things I just did. And go bankrupt.