There are two days on our calendar that seem very similar. Both Yom Kippur and Tisha B’Av share being a fast day and a number of other prohibitions. Yet, every Jew knows instinctively that there is a profound difference between the two. How do we define this distinction? My rebbi, Rav Yitzchok Hutner zt”l, put it succinctly: “Tisha B’Av, ver ken essen, who can eat? Yom Kippur, ver darf essen, who needs to eat?” Clearly, Tisha B’Av seems to be the worst day of the Jewish year. On Yom Kippur, we are like angels; on Tisha B’Av, we seem lower than the rest of humanity. Yet, there is a mystery hidden inside the misery: “On Tisha B’Av, Moshiach is born” (Yerushalmi, Brachos 2:4; Aggadas Bereishis 68; Pesichah to Esther Rabbah 11). How can this be? Is it the worst of days or the best of days? Let us explore.