I think that application requires a broader experience than just gaining the knowledge or ability to perform a task.
Let's see if I can come up with some good examples...
Okay, programming. Or language learning, even. Yeah - let's use learning a foreign language as an example.
Very few people, even after taking years of classes, are able to speak a foreign language. Actually, I would contend that noone can speak a foreign language, but that sentence is misleading without further explanation. More on that later.
It seems that people think that some day, after having mastered all of the content in their textbooks, they will magically be able to speak a foreign language. Usually, they wait until this theoretical moment to use and practice the language outside of the confines of classes and textbooks, because when they hear/read/try to speak it in the real world, it is still much to difficult for them to understand; there's too much adversity.
But, there's a problem with this approach. Textbooks and classes can be helpful for teaching you the fundamental skills; for giving you the basic knowledge and understanding -- a framework, if you will. But you absolutely have to expand on that knowledge and learn to utilize that framework in the adversity of the real world to make it functional. Language encompasses every aspect of human experience; every emotion, every thought, every thing and every action or condition that we might experience in life. That's far more than anyone could ever pack into any class or textbook, and it's something that you can only gain from using the language in the real world. There's lots of adversity to overcome at first. You won't have the words or the natural expressions to express yourself and your ideas, and you will struggle letting your personality come through. You will struggle using the language naturally, and adapting to any conversation or contect. This is because you have not yet made the language yours; it's still foreign to you. It's still a foreign language; one that you have knowledge of, and even competency in; you might even ace a grammar test, but you have not yet made the language your own. To do that, you have to struggle and use it, and use it, and use it in all of the diverse and adverse situations that you have never experienced before. You have to experience every facet of life once again through and in that new language, so that it becomes as intimate and familiar as your first language. It has to cease to become a foreign language, and become a part of you.
The same is true of martial arts which might be useful in self defense. The demands of self defense in the real world go far beyond what one might practice in the dojo. Traditional practice in the dojo does impart skill and understanding which may be of some applicable use in the real world, but it will be awkward and clumsy and unreliable until you have honed it through a diverse array of real world experience and adversity, or at least come close in your training to replicating and addressing these things. Your average person speaks a very different "language" physically than your fellow aikidoka does, and will not respond or act like your training partners; it's kind of like bringing your textbook Japanese to Japan, only to find that people don't quite speak like that in the real world, and having to adapt. If you've never experienced it before, it will take quite a bit of time to familiarize yourself with and adapt, but your formal knowledge base will serve you well in doing so.
