Some people think that happiness is to do what he wants to do, to have the freedom to choose things by themselves or by their own without doing the thing I don't want.
Some people think that happiness is doing what you want to do, to have the freedom to choose things for yourself, or as they want without being forced to do something.
Some people think that happiness is doing what you want to do, are free to choose the things by yourself or as they want without forced to do things you don't want to.