This is a great exercise in the use of imagination. It should go without saying that there can be many different answers, as the example is hypothetical. Here are a few possible story lines.
First, this homeless person may be very angry and resentful. He may want the things that other people have. He might reason: "all people make mistakes! Why do I need to suffer these things for so long!"
Second, another scenario might be that this homeless person actually believes that he deserves his lot in life. He made his mistakes in the past and now he is paying for them. He might just want the company of people and not much else. He might not be resentful at all.
Third, he might be the type of person who actually chooses this way of life, because he realizes that what other people have is not that great. They are in slavery to their possession, their mortgages, and what society says they ought to do. Who know he might have turned into a philosopher through his suffering?