Absolutely - we can't fix the world. It's a hard lesson for those of us who want to try, but we end up just getting mired in other people's crap without any real hope of helping anything.
Because we end up not helping, often the people we are trying to help get resentful of our meddling.
I learned a long while ago that the best way is to focus my efforts on those folks where I can really make a positive difference, not the long shots.
"Listen, or your tongue will make you deaf." - Native American Proverb