Private sellers aren't required to do background checks or keep records because it is considered an unreasonable burden to place on someone who is just looking to get rid of a gun and is not really "in the business" of selling firearms. This is especially true when it comes to background checks since running a proper background check on someone can be pretty expensive. That's why your local gun shop is required to do a background check on you, but the widow who gets a booth at a gun show to get rid of her late husband's guns to help cover the cost of his death and pay the bills doesn't have to do a background check on you.
Yes, correct. And I am perfectly fine with that. I may criticize and disagree with the laws of the anti-gun states out there, but if the people in those states want to vote their rights away, then so be it. I can just choose not to live there. However, the anti-gun crowd is trying to take gun control to the national level and take away the right of the states to make their own decisions on the matter.