I think the etymology of the word "nerd" has evolved to mean that you have a deep and detailed understanding of a particular subject. I more see it used as a w

I think the etymology of the word "nerd" has evolved to mean that you have a deep and detailed understanding of a particular subject. I more see it used as a way to signal that you are interested in a subject relatively more than whatever main group you identify with. So someone would call themselves a "book nerd" even if they only read a couple books a year, because most of their friends don't read at all.