I like the idea of repetition. It is the technique to master any skill. When it comes to reading and absorbing what we filter out of the entire reading, it is worth to re-read only those powerful insights out of the rest of the reading. I often type notes to form a summary of what I can put into practise and keep these notes handy and organized for the moment I need to either re-read a book summary or, simply, relate to a piece of it I need to refreshed on. I use a note taking software that gives me the power to look for notes. That matter to me from a particular reading and that I cross-reference with other readings with similar content. Hence, you can tag, search, link, etc. many books and their key relevant ideas. It saves me from having to read the entire book or search within it for a specific idea.