Thoreau: What Did the Sunset Say?

In his beautifully made and thoroughly, thoughtfully edited Walden: A Fully Annotated Edition, Jeffrey S. Cramer quotes from a letter Thoreau wrote 10 years after he left his experiment on the pond:

Let me suggest a theme for you: to state to yourself precisely and completely what that walk over the mountains amounted to for you, – returning to this essay again and again, until you are satisfied that all that was important in your experience, is in it. Give this good reason to yourself for having gone over the mountains, for mankind is ever going over a mountain. Don’t suppose that you can tell it precisely the first dozen times you try, but at ’em again, especially when, after a sufficient pause, you suspect that you are touching the heart or summit of the matter, reiterate your blows there, and account for the mountain to yourself. Not that the story need be long, but it will take a long while to make it short. It did not take very long to get over the mountain, you thought; but have you got over it indeed? If you have been to the top of Mount Washington, let me ask, what did you find there? We never do much climbing while we are there, but we eat our luncheon, etc., very much as at home. It is after we get home that we really get over the mountain, if ever. What did the mountain say? What did the mountain do?

The purpose of painting so many hundreds or thousands of sunsets is not to be the Cal Ripken of twilight, but to find out what this routine daily experience may say. What is in it. To account for the sunset to myself.