what subject do you choose if you want to write a novel?

My friend ,you don't need to choose any subject.If you able to write a brilliant novel,you don't need anybody to teacher you anything,what you really need,is your special opions of your life,of other people's life.To have that,you should live your life,and understand what have happened,learn something from them.If you want to write a brilliant novel,you need to know something which is unknow to most people,and set them down.
A writer is going to teacher other people,not be teached!