Knowing why you do something, puts the soul in your work. Without it, it's just work. I refuse to believe life is simply a long grind of do-ing with an eventual not-doing as the reward. No. Love for your work, passion for what you do, is the thing that fathers beautiful things. It's the thing that makes great companies work. Heck, it's the thing that makes life work.

You list power, status or passion as possible why's. Which leads me to believe you misunderstand what true motivation really is. Wanting to create something beautiful for the sake of beauty, to contribute in a meaningful way, to add instead of substract. These are transcending human endeavours. Status, power, money; just side-effects to the medicin that is purpose.

Even you've had a reason for pushing yourself to create. Perhaps it was that in the back of your mind you believed that you deserved to live a better lifestyle. It's your vision of the future that moves you to act. The belief that things can be different, and that you are able to effect that difference. Having a why isn't important? Having a why is the goal.