...Frodo stood awhile still lost in wonder. It seemed to him that he had stepped through a high window that looked on a vanished world. A light was upon it for which his language had no name. All that he saw was shapely, but the shapes seemed at once clear cut, as if they had been first conceived and drawn at the uncovering of his eyes, and ancient as if they had endured forever. He saw no colour but those he knew, gold and white and blue and green, but they were fresh and poignant, as if he had at that moment first perceived them and made for them names new and wonderful. In winter here no heart could mourn for summer or for spring. No blemish or sickness or deformity could be seen in anything that grew upon the earth. On the land of Lorien there was no stain."A vanished world" is the first thing to note here. The beauty of Lothlorien is something Frodo is experiencing in the here and now - it's not part of the past, but the present - but later we learn that it's something of an island in time, sealed in upon itself. It isn't really of the present, but the past. Its fate is sealed, and it's already gone, even as Frodo first sees it. Thus, for all its intense and glorious presence, Lothlorien is really part of the discourse on absence, the doomy nostalgia for a better vanished age, that permeates all of Tolkien.
You could call this conservative, in a temperamental sense: the feeling that the world's best days must be behind it. The world as it presently stands isn't heaven: on that we can all agree. There must be something better. The question is, is heaven yet to come, or has it already gone? Tolkien would say it's gone, and that all that remains is a valiant fight in a losing cause, because things are just going to keep getting worse. As a literary quality, it's tragedy, with all the beauty of tragedy; and beauty is why we love Lord of the Rings. But as a philosophy of life it's no more self-evidently true than it's opposite, the belief that things are just going to keep getting better. You could argue either way, and never prove your case: belief in a golden age in the past and belief in a coming millennial paradise are both equally acts of faith. Tolkien's faith is firmly in the past, and his faith is strong enough to vouchsafe him, through Frodo, glimpses of the perfect beauty that exists in the past. Lothlorien. Heaven.
But what struck me this time through Lothlorien was that maybe there's something more going on here than just a yearning for a past beyond all but species memory. Note the way Frodo's perceptions are described here: "the shapes seemed at once clear cut, as if they had been first conceived and drawn at the uncovering of his eyes...He saw no colour but those he knew, gold and white and blue and green, but they were fresh and poignant, as if he had at that moment first perceived them and made for them names new and wonderful."
I've felt this way. At 16, 17, 18 I could look at a tree (damn near any tree) and see so much beauty in it, so much divinity, that I felt that nobody in the history of seeing could ever have seen a tree before me. The gold of leaves in autumn was so gold that I thought I could say the word "gold" and have it mean more than anybody else could. You probably felt this way, too. I dare say anybody who was a teenaged Romantic did. There's something about youth, madly in love with nature, newly aware of beauty, that makes it think it invented these things, or invented the perception of them. And it's the very naivete of the perceptions that lends them intensity - or at least the intensity goes hand in hand with the naivete.
If you're lucky, you die young like Keats and these perceptions never dim. If you're not, you get old. As you get older, things happen - disillusionment, or just fatigue - and you lose the intensity. You may still find trees pretty, even breathtaking at times, but you're no longer able to lose yourself in them the way you once did. If you're lucky you find new ways to love them; if you're not, maybe you look back wistfully on the ecstasy that was once accessible to you, and no longer is. What happened? Is it the tree's fault? Is it yours? Or is that just the way life is? Whatever, now there's a "stain" on the land, at least for you.
In short, maybe Tolkien is writing not only about a golden age in the distant, prehistorical past, but also one in the near past, within living memory of everyone who was once young, and is no longer. About not only the youth of the world, but the youth of the reader.
I certainly didn't get that the first time I read LOTR.