However, I would still like to imagine and answer your question. I think I would probably just associate myself to rebuilding with whatever group of people I happened to be with at the time. However, I'm a bit of a loner, so eventually, I would get annoyed staying in one place, Perhaps I would wonder off to the wilderness, find a new place to live alone, after all, living out in the rural areas covered by forest is my ultimate retirement dream. Perhaps if I saw the need, I would attempt to travel out and find other surviving people in an effort to attempt to join with as many people as possible to help improve our group economy and to raise our numbers for self-defense against other groups who now that there is not law, would prefer to pillage and steal rather than just live peacefully. I know it wouldn't be like the movies, most people would just settle down with their respective groups and just attempt to peacefully survive and would likely join other groups naturally for the first decade, at least, because I think it would take a decade or two for people to truly feel isolated enough from what they once were to not join with a group of fellow countrymen in a larger community all striving for the same goals of survival. I seriously doubt there would be numerous bands of evil empirical raiders or gangs roaming the cities. Most of those gangs would lose members to local communities because their members would likely be too scared to remain on the evil side of things because they know that the justice system will be much more crude, as in most crimes will come with the death penalty by some law-enforcement militia created by those small local communities, sort of like it was in wild west times here in America. Some local crime gangs would rise to some power amidst the starvation and lack of law enforcement, but only a few that see no other option would actually join those gangs. Anyhow, it would still be foolish not to join and combine with other local communities for the benefit of the common good, and that would be one of the most important tasks that needed to be accomplished in a post-apocalyptic wasteland for three things, prosperity, self-defense, and to re-aquire the benefits of sharing still working technologies and re-figure out how to apply them in different areas for everyone to utilize. The first most important thing would be too ensure prosperity over the next winter and each consecutive winters. The second, and it's close the first, self defend-ability. The third would be figuring out how to utilize technologies and re-learn them. All of these most important things are best done by having more people in a community, thus the most important thing of all would be the longer-term goal of finding other communities of survivors and have them all join each other. This would also cut down on bandits and gangs as people would see that there is a better life than always looking over your shoulder wondering if today will be your last. We would have some problems with gangs like in the American wild west times, but the problems wouldn't be as bad as they are in the movies, they'd be bad here and there while in most places there would be no problem with gangs. I don't really think we'd have a problem with raiders and gangs until about 1 or 2 decades or so when unfortunate people are really suffering from the lack of resources that we are so spoiled with today and have forgotten what it was like when we had peace. People don't usually stay with gangs because they think it's cool, they usually do it out of feeling that they have no other option if they want to survive. However, if it's been several decades or even centuries, and we are still in a wasteland with little, if any, improvement, then it's not going to get any better. I would likely look for a community or a comfortable place to live with accessible water, shoot my food, possibly farm or be a farm-hand, and have a roof over my head. I would probably try and influence my community to focus on self-defense, political participation, but in a community that small most will likely participate in it's politics already, economic improvement, and working together with other nearby communities, and perhaps even combining with other communities to make a semi-state of communities all working together.