Who knew big words and knew how to use them? Was he a charmer or an insufferable smart aleck--or maybe both? Mark Oppenheimer was just such a boy, his talent for language a curse as much as a blessing. Unlike math or music prodigies, he had no way to showcase his unique skill, except to speak like a miniature adult--a trick some found impressive but others found irritating. Frustrated and isolated, Oppenheimer used his powers for ill--he became a wisenheimer--pushing his peers and teachers away, acting out with prank phone calls,...