Most people have to live according to their own heart to be happy.

The only person who knows exactly what you  know in life is yourself. And what you what makes you happy in life isn't going to perfectly match somebody else. In order to be happy in this world you have to "follow your heart". If somebody tells you how to run your life, where to go, what to do, how to do it, then it isn't your life it's someone else's and then your not gonna be happy. To be happy you have to do what you want to do. You know what makes you happy so why would you put somebody else in charge? Too may people in the past and even today have tried to live their life by the expectations of their parents. And some might be happy living their life like that, if they enjoy pleaseing their parents all the time. But those dreams your parents make are their dreams not yours. It would make them happy to see you do all the great things they want you to do, but it isn't always what the child wants. This is where we get movies like Step Up and Let it Shine. The teens in these movies go against their parents beliefs on how they should live their life and follow their dreams. Yes the parents don't agree with the decsions their child makes at first, but eventually the teen becomes succesful at following their dreams and get everything they hope for. Then both the child and parent are happy. They followed their dream despite the fact that not everyone was along with the idea but it is what they felt in their heart that made them choose their path. And they ended up happy. To be truley happy you have to follow your heart.