Chris Blattman tells me to cheer up about aid:
5. Most of the failures are small, while the victories are huge. Think the falling cost of AIDS treatment. Other important discoveries (they really were discoveries) were "don't have 200% tariffs on capital goods," and "Don't print money to pay your bills." Lant Pritchett compares aid to piano recitals: "kind of boring and it's tedious and most of the people are wasting their time. But every now and again by God we make a difference and when we do make a difference it really transforms economies and lives for a very long time". (Yes, we also have innovations like "let's displace large populations to new villages!" but these seem to die out faster than the good kind.)
Think about working in aid differently. Aid is hard and messy. But so are a lot of jobs. Example: You can start working in a rich-country finance ministry your whole life, suffer the slings and arrows of excessive partisanship and, if you're lucky, you'll tweak the growth rate of your country a notch. And at the end of the day you can go home and tell your kids: "I helped the citizens of this country afford to buy a second flat screen television." Now THAT is depressing.
Obviously, there was a 1-4 that you should also read.