What's the problem? This bloody stigma

When I look about me and I sometimes feel that I don't belong here or there whether this is because I have not been part of mainstream society for quite a few years or because I am still adjusting to the fact that I am just a part of it. Things are much better for me though I am able to write when and what I want, I can talk to people and look them in the eye plus the fact that I do know that most of the time I know what I am talking about. So what's the problem you might ask? It's this stigma which still seems to be attached to me in fact to anyone that's been homeless or an addict. When we are honest and tell someone we could fall back in to our old lives or habits. This invisible neon like sign seems to come on and everyone becomes wary of us and this does become a problem for anyone getting back into the normal run of things. I have been lucky I have managed to combine everything I have done with what I am still doing but when I am out looking for work or going to interviews I sometimes feel that I shouldn't mention my past but as soon as I do wham bam it's all over. So the stigma becomes attached again. How can anyone convince someone that the past is dead and buried? Is it because we all have skeletons in our closets or is it fear that once an addict or homeless then there is no cure?