[rickpmg]

Read the Four Tendencies by Gretchen Rubin.

It speaks specifically to this, and basically says if you are motivated by external forces, that's how you're wired and you should capitalize on it... it is a waste of time to try get 'internally' motivated. A lot of people are this way, and there is nothing wrong with it.

I liken it to a car that runs on gas... retrofitting it to run on diesel (or electric) is counter-productive... just tune it up so it efficient at burning gas.