Apparently one of Eru’s gifts for the Elves was their talent not only to value Beauty, but also to strive and need to preserve it. In my opinion, unfortunately this was their curse as well.
Trying to hold an unchanging perfection, Elves made their three rings, whose basic powers were to fend off changing. Maybe that strife to preserve Beauty came with their immortality, though (as I’ve mentioned before) I don’t think that it’s characteristic for any Ultimate God , with its immortality, to try to avoid change and development and keep a world static and unchanging.
Talking about Gods, Eru obviously amputate Elves from any need for change… So finally when the Three rings lose their powers, Elves decide to leave the Midlle Earth. To me that means Elves were uncapable to cope with the fast –changing environment. As if they were afraid to take the challenge of a New world born. And I thind that Eru’s Divine Plan included this as well.
So that uncapability makes Elves look almost like children. There is something quite childish and even fragile in their strange way to accept the world : as if they were bound to feel only extreme happiness or extreme grief and sadness-just like children. And less “childish “ among them were the Elves that spend more time dealing with Human or Evil or The-World-Outside, like Elrond for example. Their own worlds look very like a nursery or a kindergarten.
So if we dare to compare Human and Elves , and if the History of Middle earth is evolution or devolution- I think that Men definitely look more “mature” and “grown” than Elves. Though in the books it is implied that the Elves were the Master race, in that context I don’t think that it is right. So depending on the point of view it is evolution or devolution. And please, don’t get me wrong, I do love the Elves, I just doubt there values and there ability to cope with the Real world.
There is something more- from my Human point of view – if one is living all his long life among Beauty , he will definitely lose his ability to appreciate it with time. Because he will become a part of it. And furthermore-how can anyone say what is Beauty if he doesn’t know what is Ugliness.
When I read Tolkien’s Letters I noticed that when he talked about this aspect of Elves need to preserve Beauty, he used the word “embalming” , which to me rings the bell, that he didn’t like that so much. For me “embalming” is connested with corpses and death…. And if it is a kind of a Key – Elvish worlds look really dead to me.

If I may ask you – Do you prefer to live in a Perfect, Beautiful, Wonderful ,but static, unchangeable World … Or do you need change from time to time? Maybe it is the key to how much Elvish is your soul…:) or to the basic question: Do you want to be a child again.:))

My own opinion is that Beauty involves change, and that the other way means death! Because nothing that don’t change or grow cannot be considered perfect.
What do you think?