I wonder what Obi Wan and Qui Gon talked about over the twenty year period between Episode III and IV. Here are some topics. Discuss amongst yourselves;

1. Obi Wan jokes about his lightsaber skills over Qui Gon's after defeating Darth Maul (known to them as only a Sith).
2. They continue to guess what that Sith's name was (Darth Tater gets a laugh)
3. Qui Gon wakes Obi Wan every time he goes to sleep as an endless prank that gets on Obi's nerves.
4. They discuss fake names that Obi Wan can go by so no one will figure out who he really is. Their choice: Ben KENOBI.
5. Qui Gon trains Obi Wan on how to disarm a tractor beam..."You may need this skill one day, Obi Wan."
6. Monthly contests on who has the best Krayt dragon scream. Obi Wan seems to switch between two different styles and cannot make up his mind which to use (Lucas takes care of this in the new versions)
7. Obi Wan reminds Qui Gon every day of "He will bring balance to the Force"..."Yeah, right!"

This is all I could come up with right now. I'll add more as I go.