Meaning of the word "every book must be chewed to get out its juice" in English

What does "every book must be chewed to get out its juice" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

every book must be chewed to get out its juice

US /ˈev.ri bʊk mʌst bi tʃuːd tu ɡet aʊt ɪts dʒuːs/
UK /ˈev.ri bʊk mʌst bi tʃuːd tu ɡet aʊt ɪts dʒuːs/
"every book must be chewed to get out its juice" picture

Idiom

to understand and appreciate a book fully, one must read it carefully and reflect on its contents

Example:
As my teacher used to say, every book must be chewed to get out its juice; you can't just skim through it.
If you want to master the subject, remember that every book must be chewed to get out its juice.