"I often think that he's the only one of us who's achieved im..." — Ayn Rand quote meaning

I often think that he's the only one of us who's achieved immortality. I don't mean in the sense of fame and I don't mean he won't die someday. But he's living it. I think he is what the conception really means. You know how people long to be eternal. But they die with everyday that passes. . . They change, they deny, they contradict- and they call it growth. At the end there is nothing left, nothing unreveresed or unbetrayed; as if there had never been an entity, only a succession of adjectives fading in and out of an unformed mass. How do they expect a permanence which they never held for a single moment? But Howard- one can imagine him living forever.