Via Flavorwire:

“After he threw a raging party, breaking Dartmouth and federal law during Prohibition, Dr. Seuss, born Theodor Geisel, was fired from his job as editor-in-chief of the college’s Jack-O-Lantern magazine. However, Theodor, that rapscallion, kept writing for the humor mag by signing his work under his middle name — Seuss. Years later, when his first book was published, Suess added the “Dr.” as a joke at the expense of his father, who always wanted him to pursue a medical career.”