The helmer told Sci Fi Wire that when deciding to revisit the popular Disney series, the studio looked at how many great third movies existed in the world.
"In setting out to do three, of course, what good third films are there?" he asked. "Now, I wasn't counting series like the James Bond films, but the only one I could think of was the third Lord of the Rings film. It's a solid, good film, but then I thought it wasn't really fair, because it's part of one big story and not a sequel per se."
He continued: "But when I thought about it, that's when I personally had an epiphany and thought that I need to think of this film as part of a large story. I need to think of Toy Story 1, 2 and 3 as being one big journey emotionally for these toys, for Woody in particular, and that's what we set out to do with this film."
The third project sees Andy Davis ready to leave for college. He packs up his toys to be stored in the attic, but they get donated to Sunnyside Day Care instead.
Toy Story 3 is released on June 18 in the US and on July 23 in the UK.