Today is the first day of Adar, the happiest month on the Jewish calendar. The Talmud (Ta’anit 29a-b) famously states that “when Adar enters, we increase in joy” and that this is the month when a Jew’s fortune is especially “healthy” and good. However, no clear explanation is given as to why this is the case. Presumably it is because the holiday of Purim is in Adar, with Purim being particularly joyous, and associated with luck (Purim means “lotteries”). Yet, the same Talmudic tractate suggests that Tu b’Av and Yom Kippur were the most joyous days of the Jewish calendar, not Purim. How did Adar become so happy and lucky?