Why John Updike preferred to read from his poetry

Apologies if I've posted on this before, but last night Bill S and I talking about our writing or our plans for writing; I told Bill that I don't think I will write any more fiction but might be drawn someday to write poems. How come? Because writing fiction and writing poetry serve very different mental functions for the writer (not necessarily for the reader, but that's another topic). And I told Bill about the one conversation I was fortunate enough to have with one of our mutual literary heroes, John Updike. RISD used annually host a President's lecture - visiting author, followed by dinner. One year Updike was the guest and I (as Journal books editor) was invited to the dinner, and seated next to JU (obviously the president had nothing to say to him and wanted to sit him next to someone who did and would). Surprisingly, at his reading, he opted to read from his poems, not his fiction, and afterward I asked him why. He said that when he has a book to promote for his publisher (Knopf), he will obviously read from that, but otherwise he really preferred to read his poems rather than stories or novel excerpts. "I'm not sure why," he said. I offered: maybe it's because when you write fiction your organizing thoughts and ideas and memories in your mind and to write them, to express them in fiction, is to expel it: once you write it, it's gone. Whereas poetry is an attempt to capture an elusive thought, image, idea, observation that's passing by you, and when you capture it in a poem you have it there forever. He looked at me and smiled and said: Exactly! Obviously, he was being unduly modest when he said "i'm not sure why" - he had had these exact same thoughts, and didn't want to sound pretentious in expressing them (I didn't mind sounding pretentious). It was great to know that at my very low and amateurish level of writing I shared this perception with Updike, and I believe with many other fellow writers as well.