To learn a piece on the piano - even a simple one - has proved every bit as agonizing as writing a chapter in a book, every bit as tedious and hopeless and halting. But this is not to say that the piano hasn't helped my writing. It has, just not in the ways I expected.
To write fiction is to think that you're doing it wrong - that your work habits are inhibiting you; that you've chosen the wrong subject; that you've chosen the right subject, but that someone else has, unbeknownst to you, already written exactly the book you're laboring over.
We humans, just like the animals in our zoos, were born into bodies whose workings are both mechanistically predictable and unfathomably complex. Put in lots of sugar, and we'll get fat and sick. Confine our movement, and we'll get weak and antsy. Give us some manageable problems with which to grapple, and we'll cheer up.