There's no one solid "Europe", there is a bunch of countries that are farther from each other than states in US.

E.g. what do Spain and Poland have in common?

Obviously you dont know anything about Europe. In the 90's there was a huge migration of Polish people and you know where they migrated mostly? Spain (and Italy). And you know what?, most of my friends during that moment were from Poland (incredible good and educated people to be honest)