Jax Pavan 1
He was the first Jax Pavan. His parents named him Jax Pavan because they considered it to be a cool, original, and unique name that would help him express his individuality. He thought it was such a good name that he named both his sons Jax Pavan. They named their sons Jax Pavan. One of Jax Pavan IIIs in-laws thought Jax Pavan was a great name to name her son, so she did. It just kind of snowballed from there.
Jax Pavan 1 lived a really long time ago. He invented the galaxy's first toothbrush, a successful invention that people still use (although not some Darthipedians named <insert name here>). A bunch of toothbrush fans decided to name their kids Jax Pavan, who named their kids Jax Pavan...
And, well, you know the rest.