I think communism or not is besides the point. Poland has a strong imperial tradition where the state spanned from Baltic almost to the Black Sea. They’ve been occupying and ruling for much longer than they’ve been in a socialist camp, and that had a much bigger impact on their national identity. And, as some others noted, being close to Germany gives Poland a big advantage.

On the point of “communism”, take Romania as an example. I took a tour of the Presidential palace when I was in Bucharest. The guide was extremely negative about the communist era(when the palace itself was built), as many Romanians are. She went on and on how the dictator forced the palace construction and how terrible it was. Ironically, the palace is one of the few attraction in Bucharest. Walk just 200m away and it’s going to be rubble and desolation. In summary, I don’t think being anti-communist helps them all that much.

> Bulgaria, on the other hand, was a close ally of the Soviet Union and more historically, of Russia

Correct me if I’m wrong, but Bulgaria never was an economic powerhouse or major European power, unlike Poland. Between the Ottomans and other empires, they probably don’t have a history of building a strong economy. Being between rock and a hard place, not having resources, etc. probably contributed much more than what you say.