a customer at my part time job came in a cpl weeks ago. wanted to build shelves for her fiancé. said she had all her books in boxes & she wanted to finally get them unboxed. I made 6 shelves for her. we chatted about voracious readers & book "keeping". my brother keeps all his, my son might but I have no idea where they are. when I finish a book, it gets knocked around the house for a while & then I donate it to the library
your philosophy?
Some I keep, some I pass on to charity shops. It depends on the likelihood of me reading it again.
I don't buy much fiction anymore, but books on subjects I like - cars, tractors, cycling, I tend to keep.
In reality, I would need to live to be as old as Methuselah to re-read everything I have.
I also have the memory of a goldfish, so I probably could have got away with buying only one book in my life and endlessly re-reading it...