"Shugyo" is about internalization. The 1st time you build Redis, you learn the Syntax. The 10th time, you understand the Structure. By the 20th time, *the tool disappears.* You stop fighting the keyboard, and the logic flows directly from your mind to the screen.
In Kendo (Japanese fencing), we swing the bamboo sword thousands of times. Not to build muscle, but to remove the "lag" between thought and action. Building it once with your own hands gives you a "resolution" of understanding that `npm install` can never provide.