Context: In these lines the poet thinks himself to be a scholar. He is fond of reading books of great authors and exchanging his views with them. So he regards these books as his true friends. He also describes the likes and dislikes, aspirations and dreams of a scholar.
Explanation : In this stanza the poet says that the books serve him as a true friend. Whenever he is in a happy mood, he gets joy in reading them. Whenever he is sad and melancholy, he gets comfort and consolation. Thus the books are his companions of joys as well as of sorrows. When he thinks it, he feels himself very much indebted to the writers of these books. He becomes emotional and tears of gratitude begin to flow and make his cheeks wet.