I've changed my mind about what to be at least 5 trillion times in my life. Right now, I want to go to school for marketing and advertising, and I'm hoping I can stick with that. I've wanted to do teaching, nursing, respiratory therapy, social work, professional photography, marine biology and at one point I just wanted to quit school and spend my life doing volunteer work in Africa, or saving the whales, and holding down menial jobs (like the one I've got now) to pay my bills.
Oye. Deciding on a life path is hard work, and being forced to do it quickly and when you're young makes it even harder! So, if you want to change your mind 5, 10 or 50 times, you go ahead and do it. How can you find your calling if you don't explore your options? :)
The only cure for ignorance is education, and bullying or attacking someone is no way to educate them.