Really we don't know & all of us. Even we are unaware about this million worth question. On the other hand if you don't identify what really drives you,can't prosper in life at all. So ask yourself just to sure about it to taught yourself and if you don't taught yourself with the specific one,then you have to lead an average life through the special coined education system as"Real life depends on the real Mission"Changing in yourself means,becoming a part of the innovation"".