Once upon a time there was a terrific young actor from Belfast who seemed destined to be the new Laurence Olivier. Having wowed audiences all over the land, he was anointed as the bard's representative of earth, and younger scholars everywhere would thank him for his filmed adaptations of Hamlet, Much Ado About Nothing, and Othello, movies that made soliloquies much easier to learn come exam time.

“I was at the garden centre the other week,” says the 54-year-old Kenneth Branagh. “And a teenager – clearly doing a weekend job – came up as I was paying for the plant, saying: ‘I loved you as Iago.’ He had watched at school, of course. I love that those films make their way into people’s lives.”

So how on earth did Branagh, Shakespearean protectorate, suddenly become Mr Hollywood Blockbuster? His live-action rendition of Cinderella has, mere days after it opened, already shifted $253,616,793 in tickets for parent studio Disney. Add that to the $449,326,618 hoovered up by the same director's Thor in 2011 and we have more than adequate walking around money.

"Thor changed everything," says Branagh. "I couldn't tell you why they thought of me. I had just come off three films that hadn't done so well at the box office: As You Like It, The Magic Flute and Sleuth. They were all films I was proud of. But they didn't move the dial at all. I wasn't hot when I started a conversation with [the president of Marvel Studios] Kevin Feige. But the thing to remember was that Marvel wasn't what it is now. Sure, Iron Man had been a huge hit. But Hulk with Edward Norton hadn't been what they hoped. And Thor was the one with the most precarious tone. So they were at that stage the little train that could."

He must have had more meetings on that movie than he had for all the rest of his films combined? "Yes. There were a lot of meetings. 'Where are you in the world of comics?' 'Can you manage a budget on that scale?' I was lucky because Thor was the one I could remember from Belfast. It was the exciting one. I basically had auditioned for it with three of four pages that I wrote. And that changed how people saw me. They thought I was the Shakespeare guy. Jack Ryan wasn't the success we hoped for but accumulatively it changed the stuff I was offered."

Still, Cinderella must have been a curveball. The finished product may have paid off big at the box office but many heads were scratched when a live-action version of Walt Disney's 1950 animated musical film of the Charles Perrault fairy tale was first announced.

"Exactly," says Branagh. "When it first came to me all I thought was, this is very unusual. But that's what made it exciting and pretty challenging. And I thought, maybe there's a connection with films like The Magic Flute or Thor. They're all big pictures that have some iconic object at the centre of them – a flute, a hammer, or, in this case, a pair of glass slippers. I started to see why they would perhaps come to me with something like that. And then, when you do a bit of research, you realise this story has been around for two and a half thousand years. And suddenly my interest in myths and ancient tales and Shakespeare kicked in."

Shedding tears Branagh's Cinderella coasts along on a lovely simplicity. She's not the weedy house-frau in waiting of the 1950 film, nor has she been disingenuously given a feminist makeover. Charmingly, the film leaves its set design and costumes to provide spectacle. It uses saturated colour rather than 3D, despite what Branagh describes as "a full and frank exchange of views" on the matter.

“I cried a lot reading the script,” admits Branagh. “I wanted to present in some small way what a functioning loving family can be. And see what happens when that is disrupted.

“I suppose my own experience of losing my parents and that cycle of grief made that material fascinating. I thought if we can see those aspects we already have a different Cinderella. This is only alluded to in the original with half a line of dialogue. It was like a secret film inside a bigger film with a lot of fun with mice and coaches.”

The project initially had One Hour Photo director Mark Romanek attached. His vision reputedly proved too dark for Disney tastes. No one could say that about Branagh's delightful rendition.

“For me the light and shade is emotional,” he says. “I don’t want to create dystopian worlds. I don’t want to make the movie that tells you that everything is shit. I can’t think of anything more depressing than to offer that to the world. People have done all that to high doe, as my mother used to say. I want a way out. I’m a solutions guy.”

I am reliably informed by peo- ple who know more about such things than I, that Kenneth Branagh is "cool". It's a Wallander thing. Today, sipping tea in Dublin ahead of the Irish premiere of Cinderella, he laughs at the idea. The same actor was, aged 21, the coolest thing in theatre. Until he wasn't. His attempt to bring Mary Shelley's Frankenstein to the screen in 1994 earned unkind reviews. His light comedy Peter's Friends turned "luvvie" into a dirty word in certain critical circles.

There was, with hindsight, more than a touch of tall poppy syndrome in the way commentators spoke and wrote about Branagh during the 1990s.

“It wasn’t very nice,” he says laughing. “It happens. But you process it. Some of it I wouldn’t argue with. People didn’t like the work very much. But some of it was very personal. And you might argue unnecessary. It was a bit bruising, for sure. But no animals were harmed in the making of that picture, as they say. When I look around now, I think it’s a fashion thing. People just have enough of something. You were great, now you’re terrible. It goes with youthful prominence. And at least they didn’t have Instagram when I was starting out.”

We should not be surprised that Branagh, the middle son of working-class Belfastians, has turned out to be a resilient, adaptable fellow. Still, he can’t have ever had to answer so many questions about a dress before: the Sandy Powell-designed blue frock worn by Lily James in the film has become something of a celebrity in its own right.

“You’re probably right about that. All character actors end up playing in drag eventually. But I’ve never got around to that. This isn’t my drag movie. But it’s definitely my dress movie.”