"You never know what may cause them. The sight of the Atlantic ocean can do it, or a piece of music, or a face you've never seen before. A pair of somebody's old shoes can do it. Almost any movie before the great sadness that came over the world after the Second World War, a horse cantering across a meadow, the high school basketball team running out onto the gym floor at the start of a game. You can never be sure. But of this you can be sure. whenever you find tears in your eyes, especially unexpected tears, it is well to pay the closest attention."
They are not only telling you something about the secret of who you are. More often than not, God is speaking to you through them of the mystery of where you have come from and to summoning you to where, if your soul is to be saved, you should go to next.
Whistling in the Dark, Frederick Buechner