My given first name is “Susan”. I have never used that name, as my parents called me by my middle name since i was born, and it’s stuck. (And I’ve since taken it as my legal first name.) But I’ve always been aware of how many Susans are out there. One year in overnight camp, i shared a cabin with two "Sue"s, a “Susan”, a “Susie”, and a “Robin”.
None of us were called by our last names. Because, as mentioned above, those weren’t really ours. We were expected to grow up and take some guy’s name.