Learning the concept
Often, learning the concept within a book is sufficient; getting the general idea is enough.
If you want to grow exponentially, don’t surrender to reading every word of every publication you set out to discover. There’s no prize for reading every word and every footnote.
Soak-in the ideas. Let them resonate. But move on when you need to.
However, for the best books … every word is worth it, no matter how often you revisit the text.