You owe no one an explanation… there is no need! Some people have taken it upon themselves to explain themselves and their conditions to society. I would like to remind you that you were born alone into this world, and before you were born, society was discussing issues and conditions of other people who have made it public debate. Your life should be personal to an extent, and what you are doing with it should be totally up to you. There is no need to send out a press release or hold a press conference to explain the progress of your life to society.
The homeless are who they are because of their own reasons affected or influenced by the decisions earlier in their lives. This also goes for the prostitutes who stand at the street corners in the middle of the night, the patients at the rehear institutions, the sick HIV+ individuals and those whose lives rely on ARV’s, the cancer patients who go to chemotherapy 3 to 4 times a week, the taxi drivers at the lowest rank in society, and the domestic workers who sit at the suburban street corners under the boiling sun, just for a daily gossip with their mates, raving about their madams. Be it whatever condition it may be, whether you have failed your exam or recently lost your job. You owe no other human being an explanation.
It is your own business what goes on in your life. You may have made bad decisions in the past, which may have appeared as the best at that moment. All you need to do is learn from them, move on and enjoy the rest of your life while it lasts. There is no need to explain.