How common is it for someone to primarily be known by their last name?
I hate my first name and my middle name sounds like 'baby talk'. Thankfully, my last name also works as a first name so that's what I've been going with since I was 16/17.
Would it bother you if you found out that someone you are on a first-name basis with has been using their last name all this while? I've been told that
it feels like I've been 'putting up barriers' because actual first names are 'more intimate'. 
YABU — Yes, it would bother me
YANBU — No, it would not bother me