It's more or less correct because you must remember people don't live forever. Every time you go back more than a couple generations you're starting back at 0.

It's more or less correct because you must remember people don't live forever. Every time you go back more than a couple generations you're starting back at 0. It's why evolution is such a no brainer. Think of a creature with just a few years of life. They have countless ancestors every century, every millenia. Countless millions and billions of parents came before us.