Well, since I've been wrapping up Psych/Soc studying for the MCAT, I've been using a lot of mcat terminology in my real life and so I apologize if this response seems a little confusing.
I would say that it's important to have an internal "locus of control", meaning that you derive motivation and inspiration internally as opposed to from external sources. I know that I want to be a doctor because it's what I want to do, not because of my parents or any other external reason. As a result, I am able to avoid falling into the trap of "learned helplessness", which is a sense of false inadequacy that often results from having an overly "external" locus of control.
In addition, I like to browse sdn/other websites if I'm looking for solutions to problems like time management or study skills that I may not otherwise know on my own. As for what fuels my desire, well, I don't really have a backup plan after medicine, so if I mess this up I'm pretty much screwed lol. Hope this helps.
