Two weeks ago I returned from my Thursday night rounds, visiting homeless camps and shelters. It was about ten to midnight. At Nightwatch, all the homeless guests were fed and sent off to shelter. There was one last guy – a young man – sitting at one of the tables, pouring over a math textbook. He’s doing algebra problems. He cackles as he figures one out. I’ve been working with homeless people for more than 30 years. This was a…