As far as I can tell, most actors' main motivation is self-doubt and neuroses.
A hero is also someone who, in their day to day interactions with the world, despite all the pain, uncertainty and doubt that can plague us, is resiliently and unashamedly themselves. If you can wake up every day and be emotionally open and honest regardless of what you get back from the world then you can be the hero of your own story. Each and every person who can say that despite life’s various buffetings that they are proud to be the person they are is a hero.
