Oh, boy.
Theory is all good and well. It has its value. But knowledge gained through experience means far more to me than book-larnin'.
Read about tornadoes all you want. But the experience of surviving an F5 tornado tearing the earth apart around you will stick with you for the rest of your life. It will fundamentally change the way you think about how to behave when the warning sirens sound, and how to survive a tornado.
Reading it out of a book? Not so much. Maybe a little, but definitely not in the same way.
Similarly, you can read about algorithms and data types and programming paradigms until your head slams against the desk from sheer exhaustion. Best practices, unit testing, frameworks, standards, blah blah blah. Until you put it into practice and see it work or fail disastrously, it doesn't have the same impact on you, and you won't be able to speak about it with any kind of authority. You'll just be quoting someone else.
Give me the guy who can look me in the eye and know what the hell he's talking about over the guy who's spouting theory any given day of the week. On the other hand, it helps if he understands the underlying theory, but I'm far more impressed if he's survived the F5 tornado ripping through his company and knows what to do about it and can help us prepare for it in the future.