A rational person collects books and subject matters which are needed, and classifies and studies them regularly, and then summarize them, and notes down the summaries and memorizes them, and then proceed to next subject. Such a person even if has a weak memory, utilizes it to its maximum, and becomes like a person who has an orderly library with neat shelves. A library, with each shelf having specific books in a particular subject, and any book can be found immediately. Otherwise, it is like a person who has a library with thousands of books, but they are stacked on top of each other, and whenever wants to find a book, must spend at least two hours to look for it until it is found [1].

[1] Insaan va Sarnevesht, Shahid Mortaza Motahhari (RA), Page 144.