re: There just aren't any homeless people who are really smart.
Actually there are. A disturbingly high percentage of homeless people are ex-military and they just can't cope with civillian life any more - a lot of homeless people are addicted to alcohol and drugs... and you don't need to be stupid to suffer from either of those either.
I have a feeling that an interesting life might be a function of the variety of people you know - specifically those outside your comfort-zone. Just because someone is mal-adjusted I wouldn't assume they're not smart.