During World War I Berg spent some time in an army training camp. This experience must have been in his mind when he wrote his opera "Wozzeck". This opera became very famous. There were a lot of new ideas in it. It is not about a great hero, but about a simple man who is mistreated by people. The music, too, is very different from opera music up to that time. Although it was so modern it was a great success and made Berg world-famous. It gave him more money which, together with a little teaching, allowed him to spend most of his time composing.