When the relatively unknown Aussie Hugh Jackman landed a role in the 2000 superhero film X-Men, playing sideburn-sporting mutant Wolverine, he couldn't have predicted the fame that would follow. Nearly two decades on and the former jobbing actor is one of the biggest stars on the planet, with an Oscar nomination (for 2012's Les Miserables), a star on the Hollywood Walk of Fame, and 9.9 million Instagram followers.

"I owe it a lot," admits Jackman, who prior to playing claw-wielding, brooding Wolverine had been performing on the West End stage as chipper Oklahoma! cowboy Curly McLain. "There were 50 people in the hallway who looked exactly like me, all reading their lines, going in and doing auditions," he recalls of the career-changing casting. "But even though I was in a big movie, everyone thought it was going to fail... The moment the movie came out, everything changed."

Jackman went on to appear in high-profile romcoms and dramas (including Baz Luhrmann's western epic Australia), but X-Men's muscle-bound mutant was the role he returned to again and again - perhaps because he never felt he'd "fully cracked it".

This year, the 48-year-old is back for his ninth and final Wolverine outing in Logan (the name Wolverine is commonly known by), and the pressure was on to do his alter ego justice.

"Knowing it was the last time, I wanted to get it right, I wanted to make the definitive movie about this character," says the affable star.

"I rang director and writer]Jim Mangold, my friend, and we set about doing it. I didn't think the studio would say yes to our idea, but lo and behold, they did. So I'm very proud of the movie and it means a lot to me."

The new film is set more than 50 years after 2014's X-Men: Days Of Future Past, and sees Logan in a weakened state, caring for frail Professor Charles Xavier (Patrick Stewart), and sheltering from a world which believes mutants no longer exist.

Logan also finds himself the extremely reluctant guardian of a young girl, Laura (newcomer Dafne Keen), who can spring sharp claws just like his from her hands and feet, and is on the run from a sinister geneticist (Richard E. Grant).

As something of a surrogate father to Laura, and a prodigal son to Xavier, the film is more about Logan's humanity than his superpowers, Jackman notes: "In exploring this character for the last time, I wanted to get to the heart of who that human was, more than what his claws can do."

What does he make of his reputation as 'Nicest Man in Hollywood'?

"Could you tell my kids [Oscar and Ava] that? Because I'm the strict guy at home. I'm 'Strict Dad'," Jackman retorts, laughing.

Has he ever done anything really nasty? "Oh jeez," he says, racking his brains. "Well I played rugby for many years, so it was sanctioned, some of the stuff I was doing. What happens in the ruck, stays in the ruck, shall we say..."

He admits revisiting Wolverine for the final time was an emotional experience - a sentiment shared by Stewart, who has revealed that both he and Jackman were reduced to tears at a screening in Berlin.

"There was a moment that I came to terms with the fact this was my last one," says Jackman. "I love this character, and he's been amazing to me."

The now clean-shaven star was less upset to bid farewell to those bushy sideburns, however.

"I'm a typical guy - I was like, 'So I don't have to shave that area for six months? I'm in!' But they do look kind of ridiculous when you're walking around the street, and I get recognised more when I have them. So I'm happy not to have them," he explains. "My wife (actress Deborra-Lee Furness) really doesn't miss them. She's totally happy with them being gone!"

It was Furness, who Jackman wed in 1996, who encouraged him to get a mole on his nose checked out in 2013. It turned out to be basal cell carcinoma, a common form of skin cancer that is rarely life-threatening.

Today, he's sporting a dressing on his nose after having his sixth removed - and is keen to spread the word about staying safe in the sun.

"I figured this is an opportunity to remind people around the world to get check-ups and wear sunscreen," he explains. "All skin cancer appears about 30 years after the damage, so when you're young and you're out there on the beach and you think, 'Nothing's going to happen to me', hopefully they'll think, 'Oh maybe when I'm 48 I'll be like that Hugh Jackman guy'. Just wear sunscreen, it's so easy.

"Other people go through cancer treatment where it is life-threatening; this hasn't been that," he stresses, and after a pause, adds: "I'm fully aware that at some point, we're all going to die, and I think you need to make the most of life. You need to take risks, you need to find a way to be at peace and love your life and make the most of it.

"No one's taught me [that] more than my wife; if there's someone who makes the most of life, it's my wife, I've learnt that from her."

He extends this 'making the most' approach to work.

"Hard work is great. I love hard work. It means you're challenging yourself, you're growing, if things are difficult, it means you're pushing yourself. Those are all signs I look for in a project.

"Now as I sit here, it's all the more gratifying and satisfying," says Jackman. "I've never worked harder than I have in this movie, but I've never been more satisfied."

:: Logan is released in cinemas on Wednesday, March 1