I am motivated by my knowledge that my environment is often at odds with my inner, true self. I also know that my environment has changed my behaviors, but it hasn't modified my inner self.
So, by changing my behaviors, I know that I can get closer to living constantly in harmony with my inner, true self. That's what keeps me going.
(An example: I love to teach, but in my current life there are very few opportunities to do so. If I did nothing, I would probably never teach again. But if I do something about this, I can live a life that satisfies my inner, true self.)