What if the person is aggressive; What if they're quarrelsome; How about those who are too liberated; Even those who don't know how to watch their mouth?
This line can somewhat be taken the wrong way. In my opinion, people with an attitude like the ones mentioned above should learn to regulate theirselves.
I mean, others get their attention by telling them that what their doing isn't nice, that they have to watch their attitude, or tell them to learn when and where to be such; In filipino we say it as, "Ilugar mo naman". Then those people (with the attitude) would answer, "This is who I am", "I'm just being myself".
You can't use this line as an excuse to act immaturely.