Simon Willison quoted François Chollet:

To really understand a concept, you have to “invent” it yourself in some capacity. Understanding doesn’t come from passive content consumption. It is always self-built. It is an active, high-agency, self-directed process of creating and debugging your own mental models.

This has been my experience in my career: I have to have had a hand in building something to truly understand it. You can throw at me all the documentation, tutorials, or Slack messages you want; but my understanding from that pales in comparison to working on it myself.