Picture from scatteringthelight.Here is a little excerpt from Surprised by Joy, describing how CS Lewis realised that longing for Joy and having Joy are one and the same (and I appreciate the comment on Wordsworth).
At that very moment there arose the memory of a place and time at which I had tasted the lost Joy with unusual fullness. It had been a particular hill-walk on a morning of white mist. The other volumes of the Ring (The Rheingold and The Valkyrie) had just arrived as a Christmas present from my father, and the thought of all the reading before me, mixed with the coldness and loneliness of the hillside, the drops of moisture on every branch, and the distant murmur of the concealed town, had produced a longing (yet it was also fruition) which had flowed over from the mind and seemed to involve the whole body. That walk I now remembered. It seemed to me that I had tasted heaven then. If only such a moment could return! But what I never realised was that it had returned—that the remembering of that walk was itself a new experience of just the same kind. True, it was desire, not possession. But then what I had felt on the walk had also been desire, and only possession in so far as that kind of desire is itself desirable, is the fullest possession can know on earth; or rather, because the very nature of Joy makes nonsense of our common distinction between having and wanting. There, to have is to want and to want is to have. Thus, the very moment when I longed to be so stabbed again, was itself again such a stabbing. The Desirable which had once alighted on Valhalla was now alighting on a particular moment of my own past; and I would not recognise him there because, being an idolater and a formalist, I insisted that he ought to appear in the temple I had built him; not knowing that he cares only for temples building and not at all for temples built. Wordsworth, I believe, made this mistake all his life. I am sure that all that sense of the loss of vanished vision which fills The Prelude was itself vision of the same kind, if only he could have believed it.