Throughout my life, i've seen many people lacking this - motivation. Especially in school. And when i say motivation, i mean a genuine drive that comes from within, and not pressured from without.
Studying hard because your parents ask u to, is lousy motivation from what I know. Studying hard for the ambitions that you have, is better, but if the ambitions are selfish, i've found it to be quite weak for some people. For me, the only thing that could possibly move me to care is people. The thought that suffering happens (and i'm part of the cause) is sickening and painful.
But i digress, motivation is needed for people to function well, or you will slowly find apathy creeping into your life, without even realizing it. And this is what kills potential, its what kills dreams and hopes and ambition.
We all need to think of what motivates us, and if its not good enough, we need something better.