As his doctoral student in Regensburg from 1971 to 1978, it was my privilege to study under Joseph Ratzinger, who is recognized as one of the greatest theologians of the 20th century. He kept in touch with his former students down through the years, thanks mainly to his Schülerkreis (the circle of doctoral and post-doctoral students), which, from 1978-2013, met annually until he retired as Pope. He was, and remained all through his life as Professor, Archbishop, Cardinal Prefect and Pope, a simple, humble man.