What I never liked much in books that should provide knowledge.

[pier4r]

https://www.reddit.com/r/math/comments/8...s_i_guess/

I would make a quick analogy with annotated chess games. Something on the line "here there is a beautiful mate in 7, but I won't deprive you from the pleasure to find it". No, one can take time and try by himself, but the book should provide a solution at least.

Why? Because a book cannot talk or change, is fixed in time, so if one is stuck the book doesn't help and fail in its purpose.