That is the point he is driving home that you are not old enough to be living without parents. Parents pay for everything, feed, clothe and educate you and even 15y/os who think they are so mature need boundaries. I am sure you think you are so smart you only need them to give you a bed, clothes and food and should butt out of your life. Families are important in our lives and being part of a family is obeying family rules set to keep the family safe and protected, supporting each other, and to make sure the children do not become spoiled brats as you seem to be becoming. If your parents dropped dead tomorrow you would sh!t yourself. Life is not all fun and games. once the childhood of learning is over then you have to start supporting yourself as your parents won't do it forever. We all have to find jobs with bosses with their rules to follow, as well as society's rules. Life is full of rules and even though we don't like some of them they are there for a purpose. Life is not a free ride so stop whinging about it and understand in life we have to follow rules.
So stop acting like a whiney little kid and grow up a bit and start to show some sensible maturity as believe me if you left home at 15 you would find likely all there would be for you to survive is getting naked with fat old men and sucking their c0cks of letting them f#ck your @ss. I have seen 15y/os who thought life would be better if they got away from mom and dad's rules but generally they became prostitutes or criminals stealing to survive and ending up in Jail. Many come crawling home to mom and dad humiliated by the mess they made of their life. I have known guys like you who think life should be all fun and no rules and they became useless adults and many ended up in jail. You have a couple years of childhood left so stop complaining as then you may start having the life without family rules as long as you have your own place and income.