While I agree the terms don’t often come up in conversation, you’re at least familiar with them. You’ve often referred to yourself as a Jerseyite:
You’ve also responded to others calling themselves Jerseyans.
The terms may not be common, but they aren’t so rare that it’s not surprising that someone living in the state is completely unfamiliar with them.
Now, I’ve never heard someone from Connecticut referred to by a demonym, whether Connecticuter, Connecticotian, or Connecticutensian.