Encouragement to be patient in prayer

I'm working through Augustine's Confessions and he has this great section about how he's deceiving his mother (before he was a Christian) to move to Rome to teach a new group of students.

That same night I left by stealth; she did not, but remained behind praying and weeping. And what was she begging of you, my God, with such abundant tears? Surely, that you would not allow me to sail away. But in your deep wisdom you acted in her truest interests: you listened to the real nub of her longing and took no heed of what she was asking at this particular moment, for you meant to make me into what she was asking for all the time (86).

I thought this helpful for those prayers that seem unanswered or even answered in the negative.