How very very right you are!!!
My son is 21 now, wonderful son I might add. Never had the opportunity to cruise with him. Nor is he able to accompany us in April 2001. However, when he was young, he was never, and I mean never, allowed to run around and disturb other people in public places and he was taught not to stand in his seat at a restaurant and stare at the other party in the next booth. Further more, he was always my responsibility regardless of where we were etc. I would have been mortified if someone felt it necessary to point out the error of my child's ways! If for some reason he did become upset, I immediately removed him from the room. It would have been unconscionable to remain with a child who was upset and thereby disrupting the others!
He's always been asked back wherever we went because he was very well behaved! I read to him the article regarding the behavior of the teens last April on the Voyager, he was appalled!
It all boils down to common courtesy and thinking of others.