It might be easy to expect homeless people to just be constantly miserable. Nope. They're just ordinary people who can range from awesome to fucking assholes.
When I was on the streets last year there was this one dude who was incredibly cheerful. He bought me coffee and a banana at least once. I hit him back later when I could. He refused to go to the Salvation Army shelter for some reason and where exactly he slept I have no idea. He was over the moon when he got a tent.
You just adapt. I've been paralyzed by depression in a luxury apartment with food and a pretty lady who claimed she loved me. And I've been so pissed off by Alcoholics Anonymous and county level bureaucracy fucking me over that I've soldiered forward out of pure spite. Life's weird.
Edit: Also, I missed the chicken wire machine video. I've operated one of those before in one of many many jobs. "Operating" pretty much just involves watching, removing full spools and occasionally replacing a giant roll of sheet metal. One person can operate ten of them at the same time.