WordNet sense 1 (people who have been introduced to the mysteries of some field or activity):

initiate, initiate

WordNet sense 2 (freed from illusion):

disillusioned

WordNet sense 3 (freed from enchantment):

disenchanted

WordNet sense 4 (highly educated; having extensive information or understanding):

knowing, knowledgeable, learned, lettered, well-read, well-educated, learned

WordNet sense 5 (possessing an education (especially having more than average knowledge)):

educated