I'm aware. But none of them have ever actually met the definition of communism. At minimum, all of them still had central unitary state powers. That is, by definition, not communism. The flaw with the theory of economic transition to communism is not necessarily the communism, but the transition. It requires a unitary party to seize the means of production, and then voluntarily distribute those means to the people and dissolve the central government structure. You'll notice that that last step has never happened on a national scale in history.
I'm also not a communist, for what it's worth.