I attended Japanese school for a few years during elementary school. However, by high school, I’d forgotten most of it.  I took Japanese from 10th grade in high school, but instead of learning, we played cards and watched anime.  Therefore, I wasn’t prepared when a Japanese tourist in Waikiki asked me a question.  (I was in 11th grade then.)  I said, "wakarimasen," and she laughed and said, "oh, Japanese student!"  Exactly!