Having books across 8 to 20 different topics is good because it's not always possible to predict your day to day goals and energy level two or three months in t

Having books across 8 to 20 different topics is good because it's not always possible to predict your day to day goals and energy level two or three months in the future. Having some books on marketing, business, some biographies, some history, some light fluffy fiction, some more intense fiction, some technical books... it means when the inspiration to read about biomechanics and health hits, you've got a book on it, or if you want a light read in the park, you've got a book of good short stories, and so on.