Yes, I believe that self-reliant communities repeat old mistakes, because there is not enough work done in self-reliant communities for the community to be living in anything but poverty. Self-reliant communities usually do little to educate their children, and they usually have little medical care. They have principles, but very little skills in practice.
Self-reliant communities repeat old mistakes they have made because they fall prey to the old adage, "But that's the way it's always been done!" It is difficult to elicit change in a community that does not have a lot of influx from other communities and relies mainly on the same people doing the same things the same way they have always been done.
Communities that are not dependent and thank for themselves will continue to help stabilized themselves no matter where they reside. They are not dependent on outside sources and decision making in order to function on their own. This benefits any community that takes this approach in order to provide substance to their people.
I think that when a community is self reliant from the rest of the world, they benefit the human race a lot, and I think that we need a lot more of these communities. This way, if something goes wrong in the world, they will be fine and not in trouble.
I personally think that self reliant communities do not repeat old mistakes but the communities do benefit humanity because the communities volunteer and help their communities out a lot. I personally think that self reliant communities do have mistakes that the communities have learned from so they do not repeat old mistakes.