I'm not in law school anymore, but I was driven during law school by fear of failure, and a need to confirm that I am as smart as I thought I was - not genius (tests might say otherwise, but I know I always need to reassess what I think I know) but smarter than most. I didn't want to find out that all these years of telling myself that I was very intelligent and had just not applied myself in undergrad were a lie, and that I was ordinary (explaining away my terrible undergrad GPA, but I majored in Philosophy, so, come on).
Of course, I was right, as always! However, having excelled in law school, it put me in a job surrounded by similarly intelligent people, and its weird not always being the smartest person in the room anymore. But, I’m only better being around smarter people than I.
Oh, and cash. I wanted lots of cash to buy fun things.