"Developers do not learn programing languages. They learn to solve problems using programming languages as a tool."

Exactly. Like even mathematics and abstract thinking [Har65]. Fundamentally pragmatic, though it doesn't look like it. Our brains are pragmatic [Pri70]. Languages and knowledge is a larger toolbox for solving problems, and our brains then reward us for solving so and so problems using this or that tool. Because they are pragmatic. The result is the fastest possible learning.