Ivan might live in captivity, but fortunately for him, he still gets to see a fair bit of the world around him. However, Ivan’s description implies that everything that happens to him, or that he sees, is routine: the cars pass “constantly,” and it’s clear that the billboard’s message hasn’t changed in some time, since it’s so faded. Indeed, Ivan even implies here that he’s bored, since he wishes he had more ways to pass the time. The novelty of getting to eat a keeper’s book seems like it was a big deal for him, suggesting that he doesn’t get to experience new things very often.