While mapping out my theory about the recasting of Bunter during the investigation into "The Unpleasantness At The Bellona Club", I mentioned how Khan Noonian Singh recognized Pavel Chekov in the movie "Star Trek: The Wrath of Khan" - and yet never met him during the 'Star Trek' episode "Space Seed".
Here's the scene in the movie:
And here's an interview with Walter Koenig himself, the actor who will be forever associated with Chekov. (I apologize in advance for the quality of the sound on this video, but it doesn't interfere with Koenig's splainin.)
Considering the authoritative source*, Toobworld Central is happy to accept this as the official splainin for why the home audience never saw Khan meet Chekov on 'Star Trek'.
[And since I've been dedicating posts lately, this goes out to fellow Iddiot Jordan Hoffman.]
*Both Pavel Chekov and Walter Koenig have been inducted into the TV Crossover Hall of Fame, so I'm looking at this video clip as being inside the box......