Just watched the second episode in syndication. In it, Howard speaks to Penny in "perfect Russian" (I believe he calls her beautiful or something like that). When he went to space, didn't he say he couldn't speak Russian?
Not that I really expect them to remember a mundane detail like that, but its interesting watching some of these season 1 episodes in syndication and seeing how much the characters have changed. Sheldon seems like more of a cynical asshole in those episodes than the clueless smarty-pants he appears to be now.