fears of living jaded

I was having a go at short-story writing the other night when everything my life has led up to till now came into focus. The story was total crap, I'll admit, but somewhere along the way my strong, sardonic protagonist found himself emotionally unstable. After reading it today for the first time I realized that I wasn't writing a story. I was expressing my deepest fears of losing myself.
I'm not talking about losing my identity in the future, but losing my identity of the present. I'm an idealist. I get angry about injustice, ignorance, and the exploitation of others by others. I'm happy that I feel that frustration because I feel the world around me no matter how far away it's actually happening.
My sister once told me I turn into a college know-it-all hippie whenever I'm ranting. At first it pissed me off. Then I realized that hippies, even the know-it-alls, made strides towards social progress in the sixties because they were pissed off and made sure that everyone knew it. If I can help make the world better for just one person, organization, community while i'm here, my life will have been well-lived.
That said, when I get out of college, get a job, find my routine, and, god forbid, get rich and buy a castle in the suburbs, I fear that then I'll lose my feelings of frustration towards social injustice. I don't want to become blinded by the money I'll make, the things I want or the vanity of success, because it's not important.
What's important is working towards a world that we can enjoy. So many people concern themselves with their own enjoyment, they forget about everything else. I know I'm one of them more than I'd like to be.
I just don't want to forget that I don't have to be.