Recall some instances in which you broke a social rule in dress, etiquette, or speech. What was the reaction? Why do you think people reacted like that?
All societies or communities have a commonsense view of the world. Or we can say that communities have a sense of the ways things ought to be. Of course, all of this is socially constructed, but those in that society believe that their commonsense view of the world is the way it always was.
Now if you break social convention, there will be a reaction or at least some notice. The type of reaction or notice will be commensurate with the degree of the break of social convention. Something minor will probably not get too much attention, but something big will definite get a reaction.
Since, you ask about personal stories, let me give you two. In college, I went to a formal party with shorts on, not knowing that the party had a dress code. I was asked to go home and change. Second, while I was visiting a foreign country I accidentally offended some religious official. He called me out on it, but when he found out that I was from overseas, he understood.
The basic point is this: breaks in social convention causes notice, because they are out of the ordinary.