I guess I am motivated by self-betterment and the belief/hope that through self betterment I will elevate my status and be able to afford my tastes.
By self-betterment, I mean knowing that I am becoming more proficient, more knowledgable, more wise, or elevating my socio-economic status.
I know it is an old thought, but one of my freshmen year prefects whom I looked up to a lot hammered it home when he told me that each night before I go to sleep I should ask myself "what did I do to better myself today?". If you can't find an honest answer to that question, you wasted your day. After a while, it becomes a game with yourself to find out how many things you can squeeze into what day, and to what degree you bettered yourself. You'll find yourself being more productive, and as a result, more satisfied with your life.
I take motivation when I see effort paying off, is another way of phrasing it. I also take motivation from getting recognition for my efforts.
What demotivates me is knowing that I have to do something that is redundant or circular in nature. I do not want to be a cog in the wheel, but rather the person turning it, or the person steering whatever the wheel is attached to. I also get demotivated when another person receives credit for my effort or idea, but to a lesser extent. While I was in therapy I learned to respect and value my own opinion more than any other's, and I learned to handle disappointment more constructively. Whenever you get disappointed, in my opinion, you should just try to learn from it and figure out how to avoid or overcome it in the future, instead of letting it drag you down further. That way, at the end of the night, you can still say you bettered yourself.