CAN WE FULLY PRESERVE OUR NATIONAL IDENTITIES WHILE BEING EUROPEAN CITIZENS AT THE SAME TIME?

I think we have done quite a few years as we maintain our own nationality and at the same time being European citizens. But these facts are things for and also have things against. Being European is good to have a common market and that we can go to any European Union country without any problem, only with the DNI. But it has as much against taxes to be paid or even that often all countries are not in favor of everything that has to be approved, because there are always different opinions. These are the pros and cons of having two nationalities, but I think you can have both at the same time.