When reading a text from a different, there are a variety of ways the translation can impact one's understanding of its content. First, it's important to understand that the language one speaks can impact the way that one sees the world and the things one pays attention to. Those who have studied foreign languages know this to be true. For example, consider that in Romance Languages like French, one has to learn nouns' genders and distinguish between when using the informal ("tu") or formal ("vous") version of the English "you." This requires one to view and think about pronoun usage differently than one would when speaking English.
If the language one speaks affects the way one thinks, then it can certainly affect one's understanding of translated texts—especially literature. In many cases, the translation might cause one to understand a specific passage differently than one would have if one were able to read the passage in its original language.
These issues are deepened in the context of literary translations. When one reads a novel, one is encountering the author's artistic expression. If one has to translate the author's words, then this will impact the rhythm and flow of the story. It can also cause the author's words to feel more mechanical than they actually are. This may lead one to appreciate the book that you're reading less than one would have if one were reading it in its original language.