Einstein rather suddenly developed a passionate zeal for Judaism. “He was so fervent in his feelings that, on his own, he observed Jewish religious strictures in every detail,” his sister recalled. He ate no pork, kept kosher dietary laws, and obeyed the strictures of the Sabbath, all rather difficult to do when the rest of his family had a lack of interest bordering on disdain for such displays. He even composed his own hymns for the glorification of God, which he sang to himself as he walked home from school.28
