I met a live one at Al's Toy Barn. Remember the Buzz that was leading the gang that came to rescue you from Al's?

[Buzz has to point it out, but it still falls in with Woody's reasoning.]

But he thought he was the real Buzz, and that Zurg that followed him thought he was the real Zurg, who was also Buzz's father. They were acting out the lore from the Saturday morning cartoon!

[A cartoon falls under that 'detailed mythology' the Easter Bunny pointed out.]