When asked, just say to your parents, that you thought with you being 18yrs old, should be old & mature enough to start making decisions for yourself, as how else are you going to be confident enough to do it when you leave. & thank them for being such good parents, allowing to to do so. If they are angry, say you are sorry, but you need to start somewhere to start making some decision about your life. You did nothing wrong, and your decision then was correct. Now being at that age, decisions are something that you are going to have to do, or ask them Are you have to ring them every time you need to make a decision. Be polite and thank them for giving you the confidence to make good and correct decision. How good.