How we cite our quotes:
Grief eats away its heart for the loss of things which it took pleasure in desiring, because it wants to be like you, from whom nothing can be taken away. (II.6.2)
Easy come, easy go, right? That's the problem of loving earthly things. It's also, Augustine seems to suggest, the root of all human suffering. You can only really safely love God, because unlike everything else, God doesn't change.
Let the strong and mighty laugh at men like me: let us, the weak and the poor, confess our sins to you. (IV.1.1)
Here, it seems like weakness is a good thing. Ever heard the Bible quotes, "blessed are the meek: for they shall inherit the earth" (Matt. 5:5) or "it is easier for a camel to go through the eye of a needle, than for a rich man to enter into the kingdom of God" (Matt. 19:24)? Augustine might not be directly alluding to those verses here, but the point is that Christianity has a tradition of advocating humility and eschewing wealth and power, kind of like Christ. This is a very different kind of weakness than the weakness Augustine is talking about when he can't seem to give up earthly delights.
For the grief I felt for the loss of my friend had struck so easily in my inmost heart simply because I had poured out my soul upon him, like water upon sand, loving a man who was mortal as though he were never to die. (IV.8.1)
When we love someone or something, isn't it always with the conceit that we won't lose them, even when we know we might? It's interesting that Augustine specifically says, "as though he would never die;" he's implying that to love anything is to believe that you'll always have it. Yes, Augustine sees loving his friend as a futile act, like pouring water onto sand. But the other big personal loss that Augustine endures in the Confessions is the loss of his mother. The loss of Augustine's good friend is almost like practice for Monica's death. Does Augustine handle that death any differently?