I just read an interesting blog post by a Googler named David Wurtz. Summed up, he says that smart people should do stupid stuff. The point is that you don't have to tackle the biggest challenges to be successful; you can find something more down-to-earth and find lots of success working with that instead. A quote:

Although I endorse those  who attempt to spend their time defying gravity (the world needs these people), I simply think students simply forget that the real world is not graded by professors with untamed beards.  Students are largely unaware that they could realize just as much success, or perhaps even more success, if they point their incisive intellect at simpler, "stupider" problems. So why don't they?

The thing is, while there's always a place for another scientist hunting for the Higgs boson, or diplomats striving for world peace, we can't neglect those things that are closer to home for all of us. And ultimately, it's those simpler, more local, "stupider" problems that affect us most directly.

You don't need the fame and fortune of solving a big hairy problem to be a success; you just need to solve any problem we all face in the real world.

I've probably not done the post any justice with this write-up; go read for yourself.