According to the song by Three Dog Night, "one" is the loneliest number, and if you ask Ole Blue Eyes, Saturday night is the loneliest night of the week. Well, the saddest day on the Jewish calendar is Tisha B'Av. The thing is, most Jews don't know Tisha B'Av exists. Maybe it's because it falls during the dog days of summer when most folks are on vacation, or perhaps because it lacks the luster of the "marquis" holidays, like Rosh Hashanah and Yom Kippur, around the corner. Or it could be that Tisha b'Av hearkens back to painful moments in a time so distant, they don't capture the hearts of the post-modern Jew.

Tisha B'Av-literally the 9th day of the Hebrew month of Av-is a day of mourning. According to Jewish tradition, the 9th of Av recalls the Babylonian destruction of the First Temple in Jerusalem in 586 B.C.E., the destruction of the Second Temple by the Romans in 70 C.E., as well as a number of other tragedies, such as the expulsion of the Jews from Spain in 1492. While far less known, Tisha B'Av is similar to Yom Kippur in many of its observances: a full fast, no sex, and no creature comforts, like bathing or wearing leather shoes. It is a day for reflection, time out of time to help us see to the heart of things.

But who needs a special day to think about destruction when it's everywhere all the time? We live in a "been there, done that" kind of a world-one giant, wall-to-wall flat-screen filled with 24/7 violence to humanity of the real and fictional kind. Five more soldiers killed in a suicide bombing take their last march across a CNN crawl, while images of Darfur, hazy home video from Al-Qaeda, and the hopeful picture of another missing child flash by as we make coffee or brush our teeth.

Attached to so many dates of infamy in Jewish history, Tisha B'Av could stand as a "been-there-done-that" holiday, a symbol of our 21st-cen. world in which we are de-sensitized to chaos and devastation. Or Tisha B'Av can be the day we stop to reconsider the same old story we accept as time goes by: hatred, conflict, and destruction are facts of life.

Perhaps this is what the Talmudic rabbis had in mind when they put hatred in the spotlight while discussing Tisha B'Av. Not hatred against the Jews, mind you, but hatred within the Jewish community itself. The rabbis pinned the destruction of the Second Temple, the community's holiest place, on the rampant antipathy that raged among so-called kindred spirits. It didn't matter that they were a generation well-versed in the Bible, nor that they upheld its precepts; their failure to neutralize hatred put them in exile. The tragedy of exile is that you do not die, but have to live each day in a condition of homelessness.

The fact of the matter is that in the biblical account of the world's creation, love, not hate, is the oldest story in the book. In Genesis, we learn that God loves Adam so much that, seeing his loneliness, creates Eve. From the verses that follow, we learn that it's possible for people to love one another, be so much a part of each other, that hurting that other is like harming oneself. Hatred comes next-Cain and Abel, Jacob and Esau, Joseph and his brothers. Love, destruction, reconciliation, forgiveness-they're all in there. But any nutritionist will tell you that the first ingredient listed on a package is the one there's most of in the product.

This world is the product-it, and we, are an enormous work in progress. In an infinite universe, it's hard to say whether humanity is even in middle age, but it's safe to say it's been around the block a few times. Yet the lessons of love are still the hardest to learn. As Isaac Bashevis Singer wrote:

"The novelists never told us that in love, as in other matters, the young are just beginners and that the art of loving matures with age and experience. Furthermore, while many of the young believe that the world can be made better by sudden changes in social order and by bloody and exhausting revolutions, most older people have learned that hatred and cruelty never produce anything but their own kind. The only hope of mankind is love in its various forms and manifestations the source of them all being love of life, which, as we know, increases and ripens with the years."

On Tisha B'Av, we read verses from Eicha-the Book of Lamentations. Lamentations are regrets-for not acting when we had the chance, for wanting to undo what cannot be undone. As the world gets on in years, as each of us gets older, too, could we be the ones to learn to love with the maturity of experience and long memory that makes fast days a thing of the past? Tisha B'Av is an opportunity to imagine a world without regret, a world ripe with the possibilities that can only grow from love. And the day after Tisha B'Av is the time to build it. The morning after, we emerge from a period of sorrow by reaffirming life, love, and creation.