As promised, here is Benignus O'Rourke's rendering as it appears on p. 93on p. 93 of his edition. It does make for a very readable version: all the more pity he decided to omit books X-XIII, then.
DISAPPOINTED BY THE SCRIPTURES
So I formed the intention
of reading the holy Scriptures
to see what kind of books they were.
And this is what I found, but only later:
something that was beyond the grasp
of the proud,
something not clear to the immature.
Something simple when one first encounters it,
but sublime as one advances.
Something shrouded in deep mystery.
At that time I was not the sort of person
to accept God’s word
to bow my head and follow its lead.
But in those days I did not think of the Scriptures
as I do now.
To me they seemed not fit to compare
with the dignified style of Cicero.
My bloated pride recoiled at their simplicity.
My mind failed to grasp their depth.
Scripture is such that it grows
with little ones even as they grow.
But I was too conceited to bear to be childlike.
I was swollen with pride
and saw myself as sophisticated.
William Mallard's work, Language and Love: Introducing Augustine's Religious Thought Through the Confessions Story (Pennsylvania State Univ Press, 1994) included this thumbnail sketchthis thumbnail sketch on a variety of these translations:
Several English translations of the Confessions are available. The nineteenth-century Pusey translation remains a careful and vigorous text; yet its language is heavily archaic to the late twentieth-century ear. Two midcentury series of translated sources have included the Confessions in English: Vernon Bourke, noted Augustinian scholar, has offered a 1953 translation in the extensive Fathers of the Church series; Albert Outler, more recently a welcome authority on John Wesley, produced a 1955 translation in the Library of Christian Classics, vol. 7. The Bourke translation is a clear, literal rendering. The Outler includes helpful footnotes from time to time on major points of Augustinian thought. R. S. Pine-Coffin offers a paraphrase-translation in Penguin Books, valuable for rapid, initial reading. Comparable to Pine-Coffin is the Rex Warner translation of 1963 (Mentor Books); yet Pine-Coffin is superior in introduction and notes, and in the adept use of English, especially the striking phrase. J. K. Ryan’s translation for Image Books (1960) is a careful, close reading, yet contemporary in expression, with valuable notes, references, and introduction. Henry Chadwick has provided a new translation (1991) through Oxford University Press with especially helpful, knowledgeable footnotes, introduction, and index.