The German language has a word for the longing that C S Lewis evokes in much of his work: sehnsucht. The Wikipedia article describes it as a feeling of nostalgia for a time that we did not necessarily experience.
Here is C S Lewis giving voice to that “piercing joy” of sehnsucht.
“Apparently, then, our lifelong nostalgia, our longing to be reunited with something in the universe from which we now feel cut off, to be on the inside of some door which we have always seen from the outside is . . . the truest index of our real situation…”
“The books or the music in which we thought the beauty was located will betray us if we trust to them; it was not in them, it only came through them, and what came through them was longing. These things—the beauty, the memory of our own past—are good images of what we really desire; but if they are mistaken for the thing itself they turn into dumb idols, breaking the hearts of their worshippers. For they are not the thing itself; they are only the scent of a flower we have not found, the echo of a tune we have not heard, news from a country we have never yet visited.”