The thing to remember is people are no longer used to interacting with strangers. I don’t take offense if I don’t get a return.
That said, I see Penn Staters everywhere. Whether I’m at the restaurant at the bottom of a Polish salt mine, at the Eagle’s Nest, Tower of London, Marienplatz/Oktoberfest, Neuschwanstein, Zugspitze, Rome, Normandy, Pearl Harbor, cruises, I’ve gotten returns when I say it or have done the latter part of the greeting.
And what do you mean by “if” you wear PSU gear on vacation? It’s an unusual day of I’m NOT wearing PSU gear. I probably have enough tshirts and polos and nice shorts or mesh shorts to make it a couple months in blue and white.