That's the most lovely and exciting thing about life! No one will ever tell you your purpose so you're free to pick your own. You can have any purpose you want, you can freely choose! Not only that but you can change it anytime you want so no need to feel trapped either. My grandmother is one of my role models, after being a housewife her entire life she started writing in her late 60's and became a successful author. It's never too late =)