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)
The home town where the character lives is destroyed, there is little loss of life. However, after the disaster passes, the area is rebuilt and becomes more prosperous than ever before. (work with your DM to determine details)