Experiencing beauty

Last weekend I took the train to Florence. I learned long ago that, to combat depression, I have to behave the same way I would if I was able to feel happy. I try to tempt my former self into being, the person who is thrilled at new experiences and who finds life worth living. I try to remember the way I felt when I wasn't dulled by this numbing darkness. I remembered my first trip to Rome, how it made me burst with joy! I rode on the top of one of those double-decker touring buses. In December. In the rain. I was drenched and the wind broke my cheap umbrella. It was fantastic. The ennui that depression causes is a cheat and a liar. 
For some reason I can't explain, this made me think about what it is like to live for hundreds of years - a mythological person like a vampire or Tolkien's Elves. What depression and boredom eternal existence must bring! I think that the possibility of experiencing beauty is inversely proportional to time. It is the fleeting nature of beauty that moves us. Michelangelo was 29 when he sculpted his David. This makes his masterpiece with its technical brilliance and humanistic insight all the more remarkable. The need for learning and leaving a mark is so intense so early because we have no guarantees for tomorrow. If we could last indefinitely, would we enjoy beauty so much?