I realize that when you are learning a skill, books are the starting point to gaining knowledge. However there are certain things that memorization will not do. There are skills that can be learned faster when you are actually doing it not just reading about it. Learning isn't about just reading and memorization, it's also doing. Imagine learning swimming merely by reading a book!
The same goes for skills like programming, photoshop, social skills, speaking. You can read about it but you also need to do it.
And it's not just reading what the manual says. There is a culture, conventions and practices that go with it. There are certain habits that good practitioners of the skill do, even without thinking because they understand there are certain pitfalls and safeguards to prevent.