When I was 13 my mother died. Through my own sorrow I was aware of the great loss this was to Pop. But he made only one reference to his own misery. He said, 'To be happy every day is to be not happy at all.' He was saying to his sons that happiness is not a state you achieve and keep, but something that must be won over and over, no matter what the defeats and losses. Later that year I got a job as an entertainer in small clubs, and suddenly I knew this was the career I had been searching for. The world of the theater was far removed from the world of my father, yet I found myself returning to him time and again, for the same reason his friends did. When I was 20 I got what every actor dreams of—a permanent job! At that time, at the depth of the depression, actors were out of work by the hundreds, yet I wanted to quit that job because I needed new experiences and challenges. Pop heard me out, then said, 'There are some people who always have to test themselves, to stretch their wings and try new winds. If you think you can find more happiness and usefulness this way, then you should do it.' This advice came from a man who never left a secure job in his life, who had the European tradition of family responsibility, but who knew I was different. He understood what I needed to do and he helped me do it. For the next few years I worked in clubs, and then I got my big break, appearing in a major movie. After that I went to Hollywood, and from then on Pop lived with me and my family there. We had a big party one evening. That night I thought Pop might enjoy hearing some of the old folk songs we used to sing at home. When I began to sing, the music and the memories were too much for him to resist, and he came over to join me. I faded away, and he was in the middle of the room singing alone—in a clear, true voice. He sang for 15 minutes before some of the world's highest-paid stars. This simple, kindly old man singing of our European roots had touched something deep in these sophisticated people. When he finished there was overwhelming applause. I knew the applause that night was not just for a performance it was for a man. By saying 'to be happy every day is to be not happy at all', Pop means ______.