Most people are kinda sad because Croatia entered the Union (myself included).
Now you also occupied unchangably the place of yours in the hierarchy of global capitalism:
an erecting country, that produces cars, machinary and provides global services for a lower cost for global markets - like the rest of Central-Europe. Always only second. Never the country of innovation.
From now on, you can never give state support to a company, and can never input local money into research&development. You can never become the high-tech country with state support, with high valude-added jobs, as EU bans all these to its member states. Croatian companies are of course too weak to make all these on their own feet, so Croatia will always depend on foreign companies, and Croats will always depend on goods that needed English, French, Spanish, Italian, Dutch, etc... engineers, researchers, designers, who work for pretty expensive salaries compared to the Croatian consumer's wallet. Same here and other neighbouring countries.
Even though, I'm pro EU, since it has other benefits. Like, you can leave your country more easily.