All the time we were growing up my father would buy books and always say the same thing: "I'll read them when I retire." He retired seven years ago. And though I tried everything from leaving books where he might see them to directly telling him how wonderful a particular book was to get him to start reading, nothing worked. A nod, a shrug and the matter ended there. From Travels with Charley to Churchill's Triumph, they all met the same fate. Until a couple of days ago, my sister got him The Da Vinci Code. ''He'll read it I tell you,'' she said, "he read the blurb at the back." So what, I replied. He does that all the time. But surprise surprise, a ticket he usually uses as a bookmark is now at page 50 I think. What can I say? Thank you, Dan Brown.