The books I truly love, I've read at least three times, with pages full of highlights and notes. Re-reading a great book is worth more than reading the latest trends. Seneca wrote a bit about this nearly 2000 years ago:
Be careful, however, that there is no element of discursiveness and desultoriness about this reading you refer to, this reading of many different authors and books of every description. You should be extending your stay among writers whose genius is unquestionable, deriving constant nourishment from them if you wish to gain anything from your reading that will find a lasting place in your mind.