Why learn from a teacher

While I don't think that it is impossible to teach yourself a skill through reading, I think it is a lot more efficient to learn from a teacher. Especially when you are first starting out.

You can imitate what is written in a book, but you never know if what you are producing is good or bad unless someone else tells you. That is what a teacher is for. He tells you your mistakes so that you can improve on them, nipping them in the bud before they become bad habits. He tells you your good points so that you can continue to do so.

Without a teacher, you won't know your good points or your mistakes until someone points it out to you. By then, your mistakes may have already become a habit, and old habits are hard to change.