In news that will make you feel especially old, the original
hit cinemas over 20 years ago.
It's hard to fathom. Where did the time go? No matter which way you look at it, it's been an exceptionally long time since Mark "Rent Boy" Renton famously chose not to choose life. It's also been an exceptionally long time to wait for a sequel.
So, why now?
"I'd meet people on the tube and they'd talk to me about the characters, like quite personally," director Danny Boyle explains, sounding both enthused and bemused by this.
"They'd remember their names. People never remember the names of characters from movies. You say, 'that character that Jennifer Lawrence played,' you don't remember what her name was.
"But people remember these characters' names and talk to me about them. It made us think that if we ever had something to say we could go back to look at it again."
In print Trainspotting had received a sequel of sorts. Irvine Welsh's 2002 novel Porno had picked up where the original novel left off. But Welsh's take didn't resonate with Boyle.
Instead, he and original screenwriter John Hodge had their own crack at writing T2 10 years ago, in 2007.
"We tried and we came up with a script that felt a bit lazy, a bit by the numbers. So we didn't do it. Didn't even send it to the actors."
But that failed experiment led to an important realisation.
"You have to have a reason to go back to it again. Because that preciousness that people feel towards it, that affection people feel towards it, means you'd better not abuse that," he says.
"You better not go back for cheap, lazy reasons because they'll kill you. And quite rightly too."
Time passed. Boyle directed Slumdog Millionaire for which he won the Oscar for Best Director. Then 127 Hours, Trance and Steve Jobs. Finally, he felt he had something for Trainspotting's beloved rogues to say.
"It became a much more personal experience than you might expect," he says. "It has the fun of the original, the outrageous extremes of the original, but deep within it there's a melancholy as well. The personal thing about ageing, which is inevitable. The process of ageing."
Spud, Sick Boy, Begbie and Renton. The original gang all back together. All 20 years older. All dealing, or more accurately, struggling, with the effects of time.
"That was one of the key things for me. The shock of seeing these characters that you knew, unfrozen. Because my image of them was frozen in time," he says.
"That's what cameras, movies and television does. It captures and depicts time. That's its art form really. It is the art form of time.
"That bravado they had in the original film -which is indestructible despite everything that's thrown at them, including death - it's no longer available to them," he explains.
"They try to access it, some of the fun's there, but it's no longer available to them. They have to take stock and take account of what they're up to. It's a personal, more acute film than the first one. I don't think I've made anything as personal."
What Boyle didn't anticipate was how personal viewers would also find T2: Trainspotting.
"We had this ambition to make the two films talk to each other," he says referencing the many flashbacks to Trainspotting.
"What we didn't take account of was that preciousness, that affection. It makes people part of the conversation. Because their memories are attached to it as a point in pop culture. That intervening period is also significant to them. They look at themselves.
"So it's a bit like a school reunion in a weird way," he muses.
And because this is Trainspotting we're talking about, he adds, "some kind of bizarre reunion".