Weight of the world

"Life is a tale told by an idiot, full of sound and fury, signifying nothing"
(Shakespeare, Macbeth, Act V, Scene 5)
Over the past few months, and especially over the past couple weeks, MetaFilter has been a forum of heated debate about societal ills. Racism, homophobia, sexism, violence, poverty, ignorance, hatred, bankruptcy, and death are being discussed at length on a nearly daily basis. Reading it day by day, it's almost exhausting. There are so many things wrong in the world, that it seems no matter how hard I try, few things will change by the time I die.
I'm starting to understand the old saying "ignorance is bliss" because my big, stupid, brain keeps me up at night wondering how we as a society will ever really improve. Every day I ride through the streets of San Francisco and I'm surrounded by the destitute and the deranged. Every day I see people treated poorly due to the skin they were born into. Every day I hear people explode in random confrontations of rage. Worrying about why things are the way they are can drive a person mad. Ignorance, meanwhile, is easy street.
Science and technology march ever forward, computers get more powerful, and we can map our entire genetic makeup, but I can't help but think we're stuck with the same stupid problems and behaviors we had thousands of years ago. There doesn't seem to be a solution. Religion has tried to be the answer for thousands of years but are we any better off for it? (I'm thinking of all the religious wars that have killed people over the years and continue to do the same today, the hatred one religious group holds for another, and people that are told they are doomed for eternity from birth).
I'm also doomed with the idea that it's my duty to make the world a better place. Growing up in suburbia, one gets the sense very early on that you'll die in anonymity if you don't make a huge positive mark on the world. Fame and fortune isn't it either. I was born with the sense that I must cure cancer or improve the lives of millions in my lifetime and I've always tried to work towards that. At 10 years old, I thought it was certain, at 18 I thought it was certainly possible, but now at 27 I realize it's an unreasonable goal to set for one's self. That doesn't mean I won't stop trying though.
Life isn't supposed to be a walk in the park. If you're not meeting difficulties every day, I suppose you're just not trying. Still, it's tiring when the whole thing feels like an exercise in futility.
Stupid brain.