I've been at my current job for two and a half years. I love this place and don't plan on leaving anytime soon. Plus I telecommute three days out of the week, and you can't beat that! My previous job I was there four years. That job was ok, but after two years of it, I was so over it. But then again I was in school while I was working there, and it was a cool job to have while in school because it wasn't too exhausting.
I attribute being able to keep a job for several years to being stable. Before these jobs I would be all over the place. I would job hop like crazy. Then again it's also about finding the right job, which is not easy.
I also have to support myself. I don't really have anyone to fall back on. My mom is a wreck and my sister is no better. My dad lives in California and I doubt I'd move all the over there. Plus I have bills to pay and I want to keep everything I have so I have to make it work.
Everyone is different, so those who do, those who don't, those who are on disability makes no difference. We all struggle one way or the other.