Our neighbors have their great grandson over at their house daily. He's generally a good kid, but we've found one very frustrating trait we've tried to deal with.
He will walk in the house regularly without knocking. It is not unusual for me to be sitting on the couch reading or doing something else and look up and see him standing there. We've tried to talk to his parents and our neighbors about it, but this is their "golden" child (they have two boys). He simply cannot do wrong. When I addressed the situation, tactfully (mentioning safety concerns; if he's in the house and I don't know it and there's an emergency, I'm not going to know to get him out), and the response was "well, it goes both ways". I was a little surprised by this, so I asked when our kids had come in without knocking and said I would talk to them. They responded "they didn't, we're just saying, that it applies to them as well". And the issue was never discussed with him (he is six).
We already know that correcting him is out of the question. My wife said something to him once when he was acting unruly (as six year olds will do), and she got an earful from his mother. This boy is simply NOT to be corrected. As a result, we've had to take to locking our doors, simply to force him to knock before entering, something I don't like to do.
I feel sorry for the kid, in all honesty. He's a good and decent child, but is growing up entirely without adult guidance because his parents don't want to hurt his feelings. Because he has no boundaries, I'd say it's dead certain he'll be trouble when he's a teenager. Sadly, it's trouble that could best have been avoided by parents who realized they're not his best friends, they're his parents.
I hate to second guess anyone's parenting (and the parents of these boys couldn't be nicer people in most regards). But I do find it sad to see a shipwreck coming that I'm powerless to prevent.