Art of Cinema on Instagram: "Leonardo DiCaprio played the part of Arnie Grape so well that when he showed up for the film's premiere, many people were shocked and astonished to learn that the young actor was not actually mentally disabled. Leonardo DiCaprio said that playing Arnie Grape was "the most fun I've ever had." When getting into character, Leonardo DiCaprio remarked of it, "I had to really research to get into the mind of somebody like that. I spent a few days at a home for mentally uns