Doing and knowing. Are they the same thing? Not if you are learning to ride a bike. You can sit down with a book and study the parts of a bicycle, but this knowledge won't help you go around the block. In the end, you will have to get on the thing, find your balance and your legs. Learning to sing is much the same. Study all you want. Learn the parts of the vocal mechanism and the history of vocal pedagogy, but keep in mind that this won't help you sing unless you are a canny autodidact, which, if anything, is the rare individual. The fact is: few people are self-aware enough to learn from the written page as far as singing is concerned. And those who do? Well. They've been around the block a few times.
I'll go out on a limb here and say that I consider myself someone who has learned a thing of two from a book. That said, I've had to wade through a ton of junk. Research can be like panning for gold: you go through a lot of dirt before you find a nugget that can be useful, even revelatory. In fact, there is nothing more exciting than putting in a call slip at a library and waiting for a book that might change what you know. You might wait weeks, months, even years for that moment. But if you want to get to the bottom of things, that is what you do. You can't hurry research any more than you can learn Isolde in two weeks. It takes time. And if you keep at it long enough you begin to see patterns, and then patterns within patterns. But all this 'knowing'....what does it amount to?
The kid on the bike just wants to feel the thrill of movement, of being alive, and going downhill at breakneck speed. Whatever you do, don't 'know' so much that you forget how to ride with the wind in your hair.