I’m at a point of being stuck for a wee bit as Augustine appears to deride formal education for the more natural method of observation. But there are a few things that seem necessary to take into account, such as if he is upbraiding himself for taking this path or whether he is questioning teaching methods of forced learning of some directions of study, and of which, the simple staples or the literary prose are indeed the better and more of value.
Piled on top of this I take it are some misjudgments by his peers and scholars of his own station that may color his tone of voice.
So this must be reread, in a quiet room, with the open mind of peace.