Ok, I won't argue about it any more, particularly since you start with the position that evidence doesn't matter. Also I envy your competence in Russian. My own progress has been pretty slow, but the time I spend on it has been pretty limited. I certainly agree that mastery takes a lot of time and effort.

To rockzmom, I'm aware of what you are talking about of course (see the linked article on critical period hypothesis), but the fact that adults are less successful at learning new languages is not really germane to the question of what methods are appropriate to teaching an additional language to adults, which is what I do.

If children are much more successful at learning language than adults, and the methods used by adults are radically different than those used by children, then it seems at least possible that traditional language teaching methods are less than ideal.