[kiskis]

I know the feeling, but I think your brain fools you. You drank the kool aid of changing the world song.

Anyway I recommend two ways to go. First, list 50 companies and/or research areas in the world who you think does really world changing stuff.

Second, don't measure yourself just by the work you produce. You want challenges, then maybe try an extremely healthy lifestyle or extreme self discipline.

Third, you said you want to cure cancer. Well, if that's the case then fully understand what your role could be in that as a sw engineer. Then go for it and forget any other world changing ideas.