Why am I Irish?

It's interesting, but it seems like people have a hard time figuring out where I am from. In the states, several times I was asked if I was Irish or British. This one time, at a party, I was talking with a guy who asked me where I grew up so I said Jersey. He said, "aha! i knew it! i thought you were British." he thought I was from the Isle of Jersey. Now let's be honest. It is clearly the lesser of the 2 Jerseys. and it's also off the French coast, and not the British, though it is a British crown dependency. But I digress.
I can't tell you how many times both in the states and in the past 2 months here in Australia I've been mistaken for Irish. Maybe it's red beard. Maybe it's the affinity for beer. I was recently told that I pronounce my vowels low and forward in my mouth, for whatever that's worth, and that makes me sound Irish. I really don't know. The only people who don't think I sound Irish are Irish themselves. It's a shame my central jersey brogue doesn't stand out more, but I suppose of all the accents I've been exposed to, Irish isn't the worst to pick-up.