Why are there so many people with the surname Kim?

I'm not a Kim myself.
But my spouse's maternal great-aunt's sister-in-law, and my mother-in-law
are all Kims lol
Even my junior assistant is a Kim
And the colleague sitting next to me is a Kim
It sounds like a lie, but it's a fact
I feel like I'm bumping into Kims all day long lol
I was just thinking about it.
Maybe Kims have some kind of productive gene with a strong desire for reproduction...