For optimal language acquisition and literacy development, input should not only be interesting, it should be compelling, so interesting that are not aware what language it is in, so interesting that that you are in a state of "flow": the concerns of everyday life and even your sense of self disappears - your sense of time is altered and nothing but message matters. Compelling input appears to eliminate the need for motivation, a conscious desire to improve. When you get compelling comprehensible input, you acquire whether you are interested in improving or not.
Stephen Krashen, Professor Emeritus at the University of Southern California, has contributed to the fields of second language acquisition, bilingual education, and literacy. Krashen has published more than 250 papers and books, including Second Language Acquisition and Second Language Learning (1982), Principles and Practice in Second Language Acquisition (1982), Explorations in Language Acquisition and Use (2003), English Learners in American Classrooms (2007, with James Crawford), and Free Voluntary Reading (2011). He is credited with several major concepts including the acquisition-learning hypothesis, the input hypothesis, the monitor hypothesis, the affective filter, and the natural order hypothesis. He is also an advocate for combating misconceptions about bilingual education.