The friend I was with says that the Professor was Prince Caspian...anyone confirm this? I have only read LW&W.
No, the Professor as a child was the protagonist of The Magician's Nephew. Read the others: if LTWW is a retelling of the Gospel to shake the jaded modern out of antievagelical complacency, Prince Caspian is a retelling of the persecution and triumph of the Church, The Voyage of the Dawn Treader a disquisition on the sacraments, The Horse and His Boy a consideration of repentence, The Silver Chair a critique of secularism, The Magician's Nephew a retelling of Genesis and the traditions concerning a noetic fall (in the real world of Lucifer), and The Last Battle, the eschaton.
(And an eerily prophetic eschaton it is: the Narnian antiChrist is a fake put up by an alliance of secularists and thinly disguised Muslims.)