What does nick mean by "riotous excursions into the heart"?

Nick said, “I felt that I wanted the world to be in uniform and at a sort of moral attention forever; I wanted no more riotous excursions with privileged glimpses into the human heart.” Nick explains that, once he returned home to the Midwest, he was disgusted with the East and no longer had any desire to know what people were really like. He was convinced that everyone he met back East was immoral, and he needed to return to an environment where morality was an important part of life.