The "Yizkor Jew"
Until the 1970's, approximately, there existed a phenomenon in American Jewry known as the "Yizkor Jew." This individual would come to the synagogue basically only when Yizkor was said, especially on Yom Kippur, thus belonging to both the "Yizkor Jew" and the "Yom Kippur" Jew clubs. On Yom Kippur, he would sit in the rear of the synagogue "shmoozing," chatting with his neighbors, or snoozing. Mainly for his benefit, synagogues would estimate the exact time for Yizkor's appearance in the Service, and Services might be held up in case of early arrival at the Yizkor point, and woe to the Prayer-leader and the Rabbi if the time was exceeded.
Nowadays, "Yizkor Jews" are hard to find. This basically proves the following point: Judaism is a living body of law, custom and faith. There is no way that it can survive on sentiment alone, and the only way to maintain one's own link with past generations and certainly the only way to pass one's Jewish heritage to future generations is to make a full commitment to the Jewish way of life.