Here is an interesting web site called HowManyOfMe.com. It allows you to enter your first and last name to find out how many people share your name in the USA. There are 69 people with my first and last name. There are 89,991 people who have the same first name as me and 230,976 share my last name. And there I was thinking that I was unique.
I thought that I would test out the saying that John Smith is the most popular name in the western world. On entering John Smith I discovered that Smith is indeed the most popular last name but John is the 2nd most popular first name. There are, apparently, 49,535 John Smiths in the USA.
It turns out that James is the most popular first name with 50,214 James Smiths.
The top 5 most popular first names, in order, are: James, John, Robert, Michael, Mary.
The top 5 most popular last names, in order, are: Smith, Johnson, Williams, Jones, Brown.
Addendum: I've just searched my wife's name which truly is unique. There are zero people with either her first or last name which indicates that she herself does not exist.