My education/career choices. I wouldn't have listened so much to my parents about my course of studies (If you study business, you'll always have a job. Music should be a hobby!) I would have loved to have been a working musician all my life. Less money, most likely, but perhaps more satisfied with myself at the end of the day. Not to say that I don't have a very good life, for I do have so much to be grateful for! There are just some things I would have done differently.