You go back to them again and again and each time you learn something about thought and language. Other texts, you get through. But not these. In fact, I'm always skeptical of people who say they are trying to get "beyond Heidegger". How far did Heidegger get with Being and Time? How far did you get in your reading of Being and Time? In fact, I'd go so far as to say that Heidegger's own attempts to get beyond himself are ridiculous. (As a person, Heidegger may well have been ridiculous. So was Wittgenstein.)