How times have changed is both the subject of “T2 Trainspotting” and an inevitable topic for a meet-the-press presentation of a sequel. But the cast of “T2” said at the Berlin Film Festival on Friday that director Danny Boyle’s kinetic energy was undiminished between the original film and the 2017 return journey.

The film is a 20-years-later sequel to “Trainspotting,” the iconic 1996 British drug culture drama, that helped define the “Cool Britannia” era and the Britpop music scene.

“Danny has an amazing energy. He really powered the original film,” said Ewan Bremner, who plays the character Spud. “This time round, he has honed his energies in a very athletic way. There’s so much in his head…that he shoots very economically, very quickly.”

“We’ve all changed, but I’ve never worked with anyone like Danny Boyle. There’s no difference there,” said Jonny Lee Miller, who plays Sick Boy. Miller said that Boyle wanted to draw on his stars’ subsequent two decades of accumulated stage and screen experience, but Miller’s own preference was for Boyle to again take charge.

The original film fast-tracked the careers of Boyle and star Ewan McGregor, and to a lesser extent Miller, and Bremner.

Boyle said he wanted to make a new movie that was independent of the original but found it difficult to escape the “Trainspotting” heritage. He revealed that screenwriter John Hodge wrote a perfectly decent sequel script, based partly on Irvine Welsh’s follow-up novel “Porno.” “But I didn’t even bother to send it to the actors,” said Boyle.

The project was only fully revived two years ago after a a trip to Edinburgh, when Hodge “wrote something much more personal.” “It is not a sequel. It is a post-mortem if you like,” said Miller.

“Renton’s ‘choose life’ approach [in ‘T2’] is different…less cocky,” Boyle said of McGregor’s character. “It becomes a confession.”

Despite the post-Thatcherite exuberance of the 1996 original and the post-Brexit context of the sequel, Boyle insisted that neither “Trainspotting” nor “T2” are overtly political works.

“They are not intended as political movies, but people read into them political meanings,” said Boyle. “We were filming during Brexit, and it was a particular shock to be in Scotland” – which voted against pulling out of the European Union – “at the time.”

“T2” had its U.K. and Ireland premiere last month. It enjoys its international premiere in Berlin, where it plays out of competition.

Sony is giving “T2” a mainly European roll-out from next week, with Asian and other releases in early March. A limited release in North America starts March 17, ahead of an expanded stateside outing on April 7.