A potent conjunction of the stars and planets occurs on your birthday. you are struck by a falling star which passes through your body like it was made of mist. you awaken feeling different, as if something has been awakened from within.
Divorce: During your adolescence your parents split up and you were forced to chose which parent to live with (Work with your DM to detirmine the details)
You find yourself in love with another, wither it is a fling or something more serious is up to you. (work with your DM to detirmine if it is ongoing or terminated)