An Observation about Stereotypes

The people of Massachusetts really are into their Irish-Americanness.  You hear "Shipping Up to Boston" by the Dropkick Murphys playing when the Patriots run out onto the field or on Sam Adams commercials and you think, Sure, that song's about Boston, those things are Boston-adjacent, it works.  But there's a place in Holyoke--I believe in front of the high school, whose mascot is a knight--where there's a big shamrock painted in the middle of the road for no apparent reason; and in subbing at the middle school here I've noticed several kids with almost aggressively Irish first and last name combinations, to say nothing of the strawberry blond/redheaded and very freckled twins Bridget and Sean.  Of course there are plenty of people of other ethnicities, but I'm bemused by the breadth of this assertion of heritage.