The article addresses the social convention of responding "de nada" when someone says "obrigado", and the importance of recognizing these behavioral nuances in everyday life.
Luís Pedro Nunes is presented as someone who ended up being the target of criticism precisely for not returning a response when someone said "obrigado" to him.
The title of the piece suggests that there are people who don't notice these behavioral subtleties, which can lead to misunderstandings or judgments about others' manners or attention.
The article seems to focus on the importance of being attentive to these small social rules and the consequences that their ignorance can have on daily interactions.
