In his book Legacy of Sovereign Joy, John Piper writes:

At the age of 16 in the year 371, Augustine sneaked away from his mother in Carthage. During the night he sailed away to Rome, leaving her alone to her tears and her prayers.

How were these prayers answered? Not the way Monica [Augustine's mother] hoped at the time. Only later could she see that praying is the deepest path to joy.

Augustine himself wrote, "And what did she beg of you, my God, with all those tears, if not that you would prevent me from sailing? But you did not do as she asked you. Instead, in the depth of your wisdom, you granted the wish that was closest to her heart.

"For she saw that you had granted her far more than she used to ask in her tearful prayers. You converted me to yourself, so that I no longer placed any hope in this world, but stood firmly upon the rule of faith. And you turned her sadness into rejoicing, into joy far fuller than her dearest wish, far sweeter and more chaste than any she had hoped to find."