According to the commentators, Virgil received his first education when he was five years old and he later went to Cremona, Milan, and finally Rome to study rhetoric, medicine, and astronomy, which he soon abandoned for philosophy. From Virgil's admiring references to the neoteric writers Pollio and Cinna, it has been inferred that he was, for a time, associated with Catullus' neoteric circle. However schoolmates considered Virgil extremely shy and reserved, according to Servius, and he was nicknamed "Parthenias" or "maiden" because of his social aloofness. Virgil seems to have suffered bad health throughout his life and in some ways lived the life of an invalid. According to the Catalepton, while in the Epicurean school of Siro the Epicurean at Naples, he began to write poetry. A group of small works attributed to the youthful Virgil by the commentators survive collected under the title Appendix Vergiliana, but are largely considered spurious by scholars. One, the Catalepton, consists of fourteen short poems, some of which may be Virgil's, and another, a short narrative poem titled the Culex ("The Gnat"), was attributed to Virgil as early as the 1st century AD.

Which three studies did Virgil abandon for philosophy?