Art & Literature Through Our Ages

A truly great book should be read in youth, again in maturity and once more in old age, as a fine building should be seen by morning light, at noon and by moonlight.  --Robertson Davies

I'm going to tell a little story about art and then I want to ask you a question about books. Both of which flow from the idea expressed in the quote above. Simply put; we see, feel, sense, appreciate art and literature differently at the various stages of our life. We bring different experiences to the works and take away quite different lessons and visions.
In 1968 I was studying in Germany. I spent Easter weekend in Paris with some fellow American students. Late on Sunday afternoon we were to catch our train back to Muenster but I just had to see one more museum. The treasure of impressionist art, now residing in Musee d'Orsay, was in a different space back then and was my last stop in Paris. Fortunately, I took a friend with me because in the final room I visited were five of Monet's Cathedral Rouen paintings. He painted more than thirty of these works done at different times of day and year to catch the cathedral in different lights.
I was transfixed. To get me to leave, it took Steve actually stepping between me and the paintings, literally blocking my view and then moving me out of the room with his hands on my shoulders. We not only would have missed our train, I might still be standing there.
Some art is just that powerful. 

So to my question: What books have you or will you read in your youth, maturity and old age. I myself am not a big re-reader of books and have often times regretted taking up an old favorite that did not age well (or perhaps it is I who was showing the signs of age) but in any case. Which books do you return to?

My own list:
Lord of the Rings (3 times, every 12 years)
Catch-22 (3 times, but long ago)
Red Mars, Green Mars, Blue Mars (2.5 times, reading now)
Burmese Supernaturalism (twice)
The Heart Sutra (five or more, but it's short and available in several translations)

You? The comment section is open.