It’s a difficult thing to fast in the middle of summer. There’s the heat, the lure of a weekday routine or, on a Sunday in the US, a time to relax and enjoy. Even in Israel, when Tisha B’Av falls on the beginning of the week, as it did this year, there is that difficulty, added to the difficulty of not drinking and eating for 25 hours, of a routine hampered by something alien to daily life.It’s a question, then, caused by discomfort. Unlike Yom Kippur, which is a metaphysical fast in the sense that it’s connected to life and death, to sin and redemption, the fast of Tish B’Av is a fast that the Jewish people, and not God, decreed.In all this, there is a temptation towards rationalization or even dismissal. The options are many: to label it a fast of “the rabbis” may be one, or a fast that’s been made obsolete by the rebirth of Israel is another.Maybe some do find truth in these ideas. However, in the discomfort and in the questions that it raises lies something much more important: memory. By their nature, memories fade or become distorted over time. In its telling, remembrance loses its effectiveness. But the power of a fast, which is a complete break from the present and its constant push into the future, provides a physical stich to the past that cannot be paralleled.On this day, we have to remember because, hungry and thirsty, we have to ask “Why are we doing this?” And we remember, on account of the fast, by referring to the unspeakable horrors in the Book of Lamentations, or by reading Job, or considering what it meant for the centuries-old Jewish communities of Spain to be ousted, interrogated, converted and murdered en masse almost overnight.We remember because remembrance is the tie that connects a nation to its history -- which is the essence of its self. Without remembrance we are just a society of individuals. And without a fast, without this fast, we have no real hope for remembrance.