A friend was soliciting books for a charitable cause, and it prompted me to cull so many books! I'm guessing in the 40 - 50 range. I have a bookcase that is the dedicated gardening library, and I must consider it sacred ground or something, because it has NEVER been culled. A lot of those books are just so irrelevant to us now and there is so much good info on the internet so they are on the way out the door! Bookcase is also nice and neat and dust-free.
I read the Marie Kondo book this week just out of curiosity. I think she is a certifiable fruit loop, but her book sold millions of copies and she is WAY richer than me, so you can take what I say with a grain of salt. However, you will never catch me thanking my coat for keeping me warm, and I remain unconvinced that if I don't fold my socks correctly, they will be unable to rest and relax in the drawer. I think she did make some valid points about decluttering in bold strokes, and I certainly got rid of more books by pulling them all out of the bookcase than I would have just looking at them on the shelves. Things kind of get established and settled into their designated places, so by pulling them out, you can more objectively assess whether they belong in your home or not.