There's only a paradox if you look at self-education from a vocational / market perspective. I'd imagine most auto-didacts learn purely for the sake of curiosity and the sheer joy of it (eg. it feels good to play music well, even if only to yourself).
I have no problem spending the time / money learning something with no prospect of monetary gain in the future. Learning is an end in itself.
I think his point about making money was more about survival. We need money to live, and it takes a long time to get good enough at something that you can make a living doing it. The point is how do you make a living (not necessarily get rich) while learning to do things.
iand it would be interesting if he had developed that. What is this "high school, college, career" paradigm that we are supposed to go through in our formative years? How can we make meaningful decisions about what will make us happy when we haven't even finished developing as a person? later on it is harder and harder to deal with the cost of furthering your education.
The original inspiration for this post is that there is simply SO MUCH to be learned in the modern era, and that as we grow older and more educated, we have access to more and understand more, and this gradually compounds upon itself and becomes overwhelming.
I feel there are 4-5 closely related topics that I touched upon but didn't dare delve into, because each one would be a blog post unto itself. The "survival" lifestyle is one of them. Living with learning as an end is another.
Ultimately, I feel that learning as an end is the theme of this post, without regard to an eventual monetary gain. The paradox being, of course, that true devotion (or should I say "pure" devotion) is only possible with monetary gain as a an end, thereby eliminating the joy of pure learning.
Anyone with an inquiring mind should pursue their own learning where their curiosity takes them. What is a "worthwhile endeavor" is difficult to judge at the outset.
I would trust your own instincts and internal compass: if you are learning new things and feel "flow" when you spend time on this side project, keep at it. It will have some kind of impact.
One good article worth reading is Peter Drucker’s "Managing Oneself" (available here http://www.amazon.com/Managing-Oneself-Harvard-Business-Clas... and a little Googling may turn up other versions as well) where he stresses the importance of learning how you learn.
In my own case I have always been a connector and cross-fertilizer, trying to apply insights from one field or area to another, sometimes where they hadn’t been considered before. There are many narrow specialists out there, you should absolutely feel free to follow your Muse as long as you are learning.
I have no problem spending the time / money learning something with no prospect of monetary gain in the future. Learning is an end in itself.