Communism is gone 20 years ago.
And until recently Poles could not travel or work elsewhere without a visa. They now have opportunities their parents dreamed of.
But why this euros is so much important to Poles?
Because when there is no work you can't buy anything. many of my wife's friends are university educated and, until recently, weren't able to find decent paying work. How were they supposed to buy flats, homes, cars etc on lousy wages? Others just couldn't find work in trades they had trained in for a long time. Places like UK allowed them to work and study in a way Poland couldn't give them.
Just imagine that people who had trained for years to do a specialised job having no job. UK could pay them more as a barman than Poland could as a trained professional... or it could give them a job as a trained pro.