If a country ever implements true communism it will experience extreme brain drain and be left with only the most unskilled people.

I'm not sure where you got this idea from. I'm not particularly informed on the subject, but when I look up the dictionary definition of communism, I get this:

a political theory derived from Karl Marx, advocating class war and leading to a society in which all property is publicly owned and each person works and is paid according to their abilities and needs.

Emphasis mine. If people with more ability are paid more, then they shouldn't be flocking out of the country, right?