1 Corinthians 10:1

Moreover, brethren, I would not that ye should be ignorant, how that all our fathers were under the cloud, and all passed through the sea (KJV)

Then: For sure the Jews already knew this story, but they may nave needed to see how it fit with Jesus' teaching. After all, it took Paul several years of study to change from a Jewish mindset to an understanding of where God was headed throughout all those years before Christ. The gentile Corinthians needed to know the same information and may have also been attracted to the "knowledge" aspect. Anything new is good. And besides, who wants to be ignorant? Although Baker (p. 137) thinks they heard it before - when Paul was actually among them. Baker also keys in to the cloud as an often present sign when things spiritual happened - the ascension and the transfiguration, for instance. Dunn and Rogerson (p.1334) explain that previously Paul's argument against eating idol meat was positively oriented and that with this verse he's heading to the negative. So there's "method," just not easy to recognize.

Now: Fairly often people who know the Bible stories lack the ability to recognize their teaching points. It takes someone else to stand back and say, "Hey your problem is exactly the same as 'so and so.' Remember what he/she did?" Believers today need Christian friends and teachers to do for them what Paul does here. They need to listen, not just think that guy is going off on a tangent with unrelated, out-of-the-box stories. We all need "Paul's" in our lives.

Extra source: Cornerstone Biblical Commentary 1 Corinthians (William Baker), 2 Corinthians (Ralph Martin & Carl Toney), ed. by Philip Comfort. Carol Stream: Tyndale House Publishers, c2006.Eerdmans commentary on the Bible By James D. G. Dunn, John William Rogerson on line at http://books.google.com/books?id=2Vo-11umIZQC&pg=PA1353&lpg=PA1353&dq=1+Corinthians+9+commentary&source=bl&ots=5QeQaYWrMS&sig=S5F3KcA_TvNMyywqRiimySoUYtc&hl=en&ei=QqHPSouICIWj8AaZxqyABA&sa=X&oi=book_result&ct=result&resnum=8&ved=0CBkQ6AEwBzgU#v=onepage&q=1%20Corinthians%209%20commentary&f=false
Additional source note: The on-line advertised book First Corinthians: A commentary for today does not say if it covers any information after Chapter 8. The Contents section is abbreviated in the Google Book previews. Book is probably helpful. It does have self-study questions. On-line evaluation here: http://books.google.com/books?id=cKpy9maLuiQC&pg=PA15&lpg=PA15&dq=Corinthians+then+and+now&source=bl&ots=ZdIs9pRvsC&sig=ZMrn7l18_-IoMfNxStR3P0RynXs&hl=en&ei=lG7QSqvcB5PGlAewrNCoCg&sa=X&oi=book_result&ct=result&resnum=6&ved=0CBoQ6AEwBQ#v=onepage&q=Corinthians%20then%20and%20now&f=false