'I have offspring that didn't exist when I started making this'
It was 1991 when Tom Hanks first went into a booth at Disney Studios to lend his voice to the character of cowboy Woody.
That was before Sleepless In Seattle, before his consecutive Oscar wins for Philadelphia and Forrest Gump, and long before the world knew what a Pixar movie even was.
When the film eventually came out in 1995, the same year he starred in Apollo 13, it changed cinema forever.
It was the first feature-length film entirely created using computer animation, and it rewrote the rulebook on what an animated film could be.
"Every one of these films has been some version of a miracle," Hanks, now 62, says in wonder, days before the release of Toy Story 4.
"The first one because we were all left wondering, 'How did they do that?'
"Then the second one because, lo and behold, everything in there actually made sense and they solved all these problems.
"I would say say to them, 'Hey Pixar, how are you going to get toys across a street in this one?' And they say, 'Yeah we have like 17 different scenarios of how to get toys across the street.'
"And if they can figure that out, I guess they can figure out all the other emotional arcs that they have to play with in this.
"Then the end of 3 was... oh my lord it was like the end of The Passion Play At Oberammergau or something like that. It was this all-encompassing look at life and the lessons to be learned from it."
But it's because of this that Hanks was nervous to come back and make a fourth film.
It's been almost 10 years since the last one was in cinemas, won two Oscars (for best animated film and best original song) and was widely considered to be the perfect conclusion to a beloved trilogy. It felt so finished that Hanks never expected to make another.
"I don't think anybody did. When we first began to talk about it, they don't give us a script, they just kind of get together with you and they say, 'Here are some of the things we are planning to do'.
"And speaking for the cast, the only questions I had were 'When?' and 'Are you sure? Are you sure you want to take another stab at this?'
"Because we are just the voices and we sweat blood in order to get this thing out. They have to work on it for the better part of five or six years from start to finish and if they screw up... man, they are toast, they don't want to go through that."
Luckily they did not screw up. The new instalment finds Woody, Buzz Lightyear (voiced by Tim Allen) and the whole gang of toys far from home and discovering old friends and new ones on an eye-opening road trip.
While new stars have joined the cast, including Keanu Reeves, Christine Hendricks and Jordan Peele, returning to Woody was an emotional experience for Hanks, whose life has changed so much since he first uttered some of the cowboy's famous pull-string catchphrases.
"I recorded as Woody for the first time in 1991, in Studio B at the Disney Studios, with Doc the engineer. My last session for Toy Story 4 was in Studio B at Disney Studios with Doc the engineer. It was a big deal," he reflects fondly.
He was recently at Disneyland with his wife Rita Wilson and some of his grown-up children when the legacy of Toy Story really hit him.
"They say it's a franchise, when it's the character you go back for, but I don't know if I can put it in that way.
"We were at Disneyland for one of those big, every character jamboree kind of light shows, a Mickey Fantasia, that kind of thing.
"At the end of the show was this huge steamboat coming by, a paddlewheeler and every Disney character in creation is on it.
"There was Mickey and the big bad wolf and Captain Hook and Pinocchio
and all of the princesses, all the way through the ages and there on the
boat too was Woody and Buzz and they were doing a choreographed dance and everybody in my family was amazed - 'Oh my, oh Dad, you're going to be there for the rest of time'.
"And that was like a moment equal to anything that has ever come at us in the course of the movies themselves."
Indeed, taking his family on the Toy Story journey has been as much a part of the experience as any other.
"I have offspring that didn't exist when I started making this. I have got grandkids now," he marvels.
Recently, he sat down to watch Toy Story 2 with one of those grandchildren.
"I had not really seen it since it came out and my granddaughter was over and she's only three and she was seeing it for the first time.
"Her reactions were as perfect as perfect can be, she was laughing and saying, 'Oh no, oh dear'. She actually said 'oh dear' at one point!
"And I thought, 'Well this is a gold standard. I am so fortunate to have been smart enough to say sure, I will do that.'"
Toy Story 4 is out now out