Don't follow Marie Kondo's advice to give your books away - you'll regret it

 A couple of  years ago, I read Marie Kondo's The Life Changing Magic of Tidying Up and one of its recommendations was to part with a bunch of books you don't use. I dutifully followed it and gave 1 bookshelf of books to Value Village (keeping 1 bookshelf of books for myself).

How I regret that decision.

Years of accumulated books, books I wanted to read someday, books I want to read today – gone, just like that. I warn my fellow bookophiles to not follow Marie Kondo's advice. Do not part with your books. Or if you must part with some, part with the ones you hate. Keep the ones you haven't read yet but plan to read someday, or the ones you plan to re-read someday.

Some books I regret throwing out:

• My undergraduate physics textbook (Halliday and Resnick). In fact, all of my university textbooks. Engineering Physics was my major and I just threw out everything I'd learned. Fortunately bookfinder.com lists an old edition of Halliday and Resnick for $20 so I will at least recoup that.
• A great undergraduate biology textbook – I think it was by Mader.
• Dialogues of St. Catherine of Siena. Never got around to reading much of it, but I'd like to sometime.