When I was on my writing mentorship, Clive Cussler told me of a man who wanted to learn to write. He copied all of Moby Dick by hand. Every word, every punctuation mark. When he was done, he tossed the pages overboard and said, "Now I know how to write."
At the time, my joke was that he hadn't learned to write. He had learned how to write like Melville.
I don't mind sharing this: I'm a survivor of Wernickes encephalopathy. Look it up if you'd like. I'll wait right here.
When I got out of the hospital, I discovered I couldn't string words together and make stuff make sense. It scared the shivin' lit out of me.
I started typing novels. Lots of novels. Word. For. Word. Eventually, I started to re-awaken. We're talking a month of copying while I tried to rebuild my brain. Eventually, a bit at a time--a phrase here, then a sentence, then a paragraph--I started to add to my favorite novels.
I deleted the results when I was done, effectively "tossing them overboard." The exercise worked.