It's an ending that has very possibly produced an ocean's worth of tears, not to mention countless awkward moments for children mildly embarrassed by their parents suddenly turning into waterfalls. "Um, dad, it's a movie about a toy cowboy."

But the sentimental crescendo of the Toy Story trilogy was real. The films' young boy, the one whose name was emblazoned on the bottom of Woody's foot, had grown up. Andy was going to college.

The fate most feared by the toys - boxed up in the attic - was miraculously avoided when Andy gifted his beloved playthings to a young girl named Bonnie.

As he drove off, after one last imaginative romp in the yard, Woody watched Andy go like a wistful father. After three brilliant and heartfelt parenting parables that ruminated on ageing, loss and impermanence, this was the final goodbye. Goodbye to Andy, yes, but goodbye to childhood. "So long, partner," said Woody.

Big gulp.

The finale was immediately received as a classic Hollywood ending. "The chances of topping this one are infinitesimal," New York magazine wrote at the time. Toy Story 3 won the Oscar for best animated film.

Everyone, including the film's makers and cast, believed they had neatly, perfectly wrapped up their trilogy.

But, of course, that wasn't it. Toy Story has returned, nine years later, with Toy Story 4. In today's movie business, nothing is safe from ongoing sequelising, not even a story about the very necessity of letting go and making peace with the passage of time.

That movie franchises have been extended well beyond their natural cycle is nothing new. But Toy Story 4 may mark when Hollywood officially gave up saying goodbye.

It's probably a fool's errand to wish for prudence from a corporate-made, multi- billion dollar property that was, from the outset, designed to sell as many toys as it jerked tears. And, for some, Woody is again coming to rescue.

The Walt Disney Co. release will break a spell of underperforming sequels.

The box office has recently slumped about 7 per cent below last year, partly due to a string of disappointing returns for badly reviewed (or just plain bad) sequels: Dark Phoenix, The Secret Life of Pets 2, Men in Black: International.

As Jeff Bock, senior box office analyst for Exhibitor Relations notes, it's difficult for any studio, even Disney, to leave $US1billion on the table.

"Audiences might not actually need Toy Story 4 but theatres desperately need it," said Bock.

"It's very reflective of where we are today with sequels and continuing sagas. We're at a point where three is no longer the magic number. It's beyond that."

Though many reviewers have questioned its necessity, the film rates 99 per cent fresh on Rotten Tomatoes.

Sequels have always been a somewhat touchy subject for Pixar. Since its groundbreaking first feature, 1995's Toy Story (the first full-length computer generated animated movie), Pixar has, for much of its existence, eschewed repetition for originality.

The studio's next two releases will be originals: Onward next March and Docter's own Soul, in June 2020.

And given Pixar's unique stature as one of Hollywood's few remaining factories of fresh storytelling capable of reaching mass audiences (its last original, Coco, grossed more than $US800 million), some are rooting for Toy Story 4 to - really this time - be Woody's last go-around. Not because they won't watch another one, but because they will.

Not everything is meant to keep going for infinity and beyond.