Interesting fact about sushi: Originally, sushi was not a dish at all, as we know it today. In ancient China and Japan, sushi was a way of preserving fish: it was salted and placed between layers of rice, which served as a means of preservation. The rice was discarded and the fish was consumed. Over time, this method evolved, and in the 19th century, nigiri sushi appeared in Japan, where rice and fish were served together, giving rise to modern sushi culture.
Found this out when I was at a sushi restaurant.