Before Twilight became a princess, she was Celestia's prized pupil, and a real brainiac, always reading books and studying. Didn't seem to know much about friendship, until she was sent to Ponyville and made some friends and defeated Nightmare moon. If you ever need any help on any subject, Twilight's you girl, with every book you can think of.
Credit goes to Angus or Ju8Code, sorry about that if I forgot