Hey, I am a Pole so maybe I could anwser this a little bit better and give some historical context; I hope you don’t mind @chessna2 :)
What people need to understand first, is that no, we don’t hate current Germany.
Now about Poland and Prussia..
Well, first we must understand that Historicly, Poland and Teutonics Knights, were not only Enemies, but also Allies. They started to be Enemies when in 1308 TO Took Gdansk (or Danzing); From Poland, and they even signed a Peace treaty in 1343. Those two actually did not have such bad relations as it is often showed; but they did fight and had arguments with eachother. Especieally in court! :D Also you should read about Second Peace of Thorn (1466)!
what people often forget about Prussia is that he used to be: Duchy of Prussia and those two, got along more or less.:) Just read the Wikipedia Articale I linked!
So no, those two were not bitter enemies all the time; xD. And Poland and Lithuania were not always friendly with eachother! (Tbh those two have made bad things in the past).
(Branderburg is also someone that needs to be written more about, as he way the key of creation of the state of Prussia!)
So Poland and Prussia (with Banderburg during the Partitions, there was also him there! aND heck those two even tried to be allies DURING THE PARTITIONS! Polish-Prussian Alliance.
They were not as bitter enemies as often showed .So I am sure Hungary would make them even bigger friends, as also the fact that Poland and Hungary see echother as Siblings.(At least in my perspective, as those two are friends since… o guess 1000 years now?) Just read those two things: Poland-Hungary and Pole_and_Hungarian_brothers_be..
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Also, I don’t think as a society, we are still mad about people who were dicks to us, cause we were dicks to other’s as well sometimes. :) I am sure on the Internet you would find people being mad about Historical events, but it’s the case with people from every country I think. I think If you asked a random Pole on a Streat about it he would say he isn’t mad about the event that took place 300 eyars ago, We are not mad for Swedes Making us a cultural dessert, just as we are not mad about Austria letting our people starve. See Galician Famine. and Swedish Deluge. It’s just history to us.
If anything, our scars in the 20 century can still be fragile and if mentioned in the wrong context make some of us mad, but we often try not spread our hatred against People. There are cases of that hatred in Poland of course, but i wouldn’t say it’s cummon. We often say we Hate Russia as a country, but not Russian People. it doesn’t mean Older people don’t hate germany or Russia, but it’s still not all of them. We are able to distinguish between State and People. With Current Germany it’s more about Trust/Distrust I would say, so Poland doesn’t Hate them, we aren’t afraid of them, but I am not sure they are friends; because If anything, Poland doesn’t trust him enough. Like Cheesna Said, current Political situation makes it a lot easier, Germany tries, but Poland just can’t bring himself up for it. So i think that Poland wants to be cologues with Germany, but not friends; just not yet. But they are on the right path I belive. :)