I've been here for nearly 20 years and have never once seen anybody dancing the Polka.
So that statement makes you (one person) an authority ?
Here in America when the Polish people put on a Polish Festival they ALWAYS have a dance floor
with Polka music and Polka dancing. ALWAYS ! (And more then enough beer)
Same with any Polish wedding that you go to.
You are not from here, probably have never been to The United States of America nor ever will, so
as you said,
Perhaps this thread would be more accurately titled 10 things that show you think you're Polish but aren't.
Very few Poles would consider a person to be Polish just because one of his great-grandparents was Polish.
Who told you that !
Whoever did is lying to you.