Why is reading or writing something different from doing something?

First consider reading. Reading is (usually) a solitary activity, with no feedback. Without feedback, there's no check on what you believe you're learning.

Now, writing. Unless you put your writing in the hands of someone (or perhaps some computer analysis app), there's also no feedback, so there's no check on whether you wrote sense or nonsense.

When you do something, you interact with the real world, and the world responds in some way. With the world's feedback, you have the possibility of learning, confirming, or disconfirming something. That's why we strongly favor experiential learning over, say, lecturing or passive reading or writing.

If you want to teach somebody something, don't just send them to a book, or, even worse, tell them what you want them to know. Instead, figure out a way to have them experience the situation in which the learning applies.

After they've had the experience, you then might want to send them to a book where they can read about what they experienced.  Alternatively, you might ask them to write about their learning and have you read what they wrote.

You can try this out:

Step 1. Write a sentence or two about what would happen if you tried to move your desk six inches (15 cm) to the left or right.

Step 2. When you finish writing, get up and move your desk six inches (15 cm) to the left or right.

Step 3. What did you learn in steps one and two?

For a far more thorough answer to this question, see my four-volume series on Experiential Learning 

<https://leanpub.com/b/ExperientialLearning>

Then do some of the experiential exercises you find there.