This paper investigates whether it is a good idea to choose a book that interests you and read it through from the beginning to the end learning all the new words you meet. For the analysis, it is assumed that learners already know the most frequent 3,000 words of English. The criteria used to guide this investigation include the number of unknown words met, the usefulness of the unknown words, the density of the unknown words, and the number of repetitions of the unknown words. Reading a whole book intensively is not a good idea unless the book is a graded reader, a technical text in a relevant subject area, or a set text that would be examined as a part of assessment. Where learners need to do such reading of unsimplified texts, they should be strategic in dealing with unknown vocabulary. Keywords: word learning, word learning strategy, unknown words