The things that inspire people vary wildly. We (I) can't answer this without knowing more about you (possibly more than would make sense to share in a public space). Are there particular things that have made you feel like humans are hopeless?
There's a narrow subset of people who are inspired by the all-encompassing vision of a utopian future that Harry desires. I think most people are inspired by more specific things - addressing issues of racism that they have particular exposure, addressing specific issues of government corruption that they care about, etc.
Are there things you care about that are more specific than "fix the entire world?"
Eh, how can I put this... I used to think I could make huge improvements in that sense through the invention, perfection, production, and distribution of useful machines. Hence why I decided to become an engineer rather than an MD as my parents intended: I thought I might help more people the first way rather than the second. But then I find out about the FAI, the ultimate machine, which, in sixty years or so (the time I thought it would take me to cause any actual change), would make all my efforts as a drop into into the ocean... And I'm cmpletely useles...
Update: Discussion has moved on to a new thread.
The load more comments links are getting annoying (at least if you're not logged in), so it's time for a new Harry Potter and the Methods of Rationality discussion thread. We're also approaching the traditional 500-comment mark, but I think that hidden comments provide more appropriate joints to carve these threads at. So as of chapter 67, this is the place to share your thoughts about Eliezer Yudkowsky's Harry Potter fanfic.
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: one, two, three, four, five, six. The fanfiction.net author page is the central author-controlled HPMOR clearinghouse with links to the RSS feed, pdf version, TV Tropes pages, fan art, and more, and AdeleneDawner has kept an archive of Author's Notes.
As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: