Why not use first names ?

Posted by Ok-Willingness-7870@reddit | AskAnAmerican | View on Reddit | 75 comments

In my culture where have the names like this " The person name, his father , his grandfather, father of grand father, (and so on), Tribe name" Though in documents we usually use the first name, father name and tribe name. And with people we call each other by our name or tribe name.

It is never sensitive to use our name which Americans might consider a first name? So I'm not understanding why first names are very sensitive to use in the first place. I understand that using the last name is the more formal one and middle name usually rarely known to others (I think?) and first name for close people.

So I'm not sure how this system exactly came to existence and why some people would be offended even if you used their first name.