I was thinking about how the point of reading isn't to literally 'internalize' what you've read. When you're engrossed in a piece of literature, you don't remember the specifics of the last page you read. What's more important is what the book is doing to your mind as you read -- it triggers a set of processes that force you to imagine and therefore form connections that you haven't made before, even if subtle and unrelated to the content of the book.

It's the same with writing. Writing isn't just a way to produce a good piece of writing, it's what the process of writing does to your brain as you think aloud, connecting words and sentences together. The same with painting, gardening, and organizing your stamp collection. The final 'product' isn't actually important. The significance lies in the process of immersion from the creator and the people who witness it.