I enjoyed this essay, "The Books That Made me" by Penelope Lively. It has some nice insights. It appeared at Unherd--the link is here. I post a few quotations from it below.
Books beget books. Intertextuality, the critics like to call it. I am at the end of a writing life; I just read now. So, the process whereby reading so often became writing is over, for me. It has been an almost unconscious process, from childhood on: I have read for enjoyment, for instruction, for education — but most of all in the serendipitous way that has supplied the essential prompts for 50 years of writing fiction.
About 3,000 books line the walls of my house. Most of them I shall never read again, but they must stay there. They define me; they remind me that I thought this, was interested in that; they reassure me, as I hurtle towards 90. Occasionally I shed a few books, but to get rid of many of them would be like discarding part of my mind.