"They don't sense the danger. Street people have their throats slashed regularly in battles over clothes and food. And nobody knows or cares how often.
"I'm a middle-aged grandmother. I've been raped at knife point and put out of a vehicle in zero weather atop a Tennessee mountain in the middle of the night."
Joan learned long ago to endure the contempt the rest of us show as we carefully avoid making eye contact.
"My experience," she says, "is that no one really cares if people are out on the street hurting. They are just glad it's not them." In telling her story, I call her Joan. But that's not her real name. I know what her real name is. But she's asked me not to use it. She fears trouble that might come from publicity. Joan doesn't seek notoriety. She wants only to educate us to the hell of living on the street.
She is a realist. Joan understands that she has become a member of a subculture that none of us wants to admit exists.
"We are people who can never become integrated into society again," she says. "Some of us are well-educated and once held good jobs. Others are drunks or drug addicts. A good percentage are simply crazy people who once would have been housed in institutions."
Joan's life crashed around her after her 21-year-old son committed suicide. She says she suffers from disabling migraine headaches and back pains that make it impossible for her to hold a regular job.
The only thing she maintains that remains as a link to the person she once was is her Arizona driver's license.
So her day is spent like that of all of the homeless we see pushing carts along the sidewalks or sitting on park benches or city benches, almost as if waiting for someone to take them on a journey.
She keeps to herself because talking to other homeless people can lead to familiarity, and then trouble. She has never met a man on the street who did not eventually want sexual favors from her. And there are some men on the street who are too dangerous.
Every day Joan must find food, find a place to wash, and a toilet. "These things are imperative to me," she says. "I learned to carry a bottle of water with me that can be filled in a park. You can also wash and use the bathroom in parks. But you must be careful about parks, too. If you are seen too regularly, the police will move you out.
"People won't give you a glass of water. Instead, they will call the police. Most days I hang out in various parks or go to the library. Each day I go on forays of what we call Dumpster diving for cans, food and clothing.
"The only money I get is from collecting cans at 28 cents a pound. I collect enough cans to pay for a Circle K hot dog and a soda, as well as money to wash my clothes.
"I keep myself as clean as I possibly can. I must try to hang on to my mind in the midst of all this."
As you can imagine, none of this is easy for Joan. Days are filled with endless hassles and small terrors. If she sits under a tree in a Mesa park, the women playing tennis will call the police.
"My sin is that I have invaded their space," Joan says. "They do not want to be reminded that they are in danger of ending up like me."
One day Joan was arrested in Tucson for falling asleep under a tree. You instinctively know that when she tells this, she is not making it up. Not long ago, a friend of mine who is a physics professor and a Princeton graduate came to visit. He went to Encanto Park and lay down on a park bench. He was promptly threatened with arrest by the police.
This is a town with incredible numbers of homeless people. We refuse to bear any responsibility, and turn our guilt into anger whenever they cross our paths. Most times we succeed in putting them out of our minds. Our only wish is that they would disappear. It makes us uneasy to look at them.
"I have become a throwaway object," Joan says. She is right, of course.
One thing that we can imagine is the horror and despair of being forced to live such a life.
Joan says: "I have seen people with broken bones trying to survive. But even a healthy person is an endangered species on the street."
It is a world in which the strong regularly attack and destroy the weak.
"Knife wounds are a big thing on the street," Joan says. "Many people get their throats cut over the smallest articles of clothing.
"Knives talk. Everyone out there on the street understands that language."
She tells her story for one reason. Joan says that if we know a little more about them, perhaps we'll understand that those figures shuffling about are actually real people.
These days, everywhere you look, there are signs on cars that read: "Go Suns."
On her shopping cart, Joan has placed the following printed message:
"I am a stranger in a strange land.