director danny boyle says that nostalgia, even to the point of denial, is a central theme in the film. >> one of their problems is that they imagine, as men often do, that they can still live like they were 20 years old. >> reporter: you're saying this with a smile, that you feel it yourself. >> very much so. i mean, it's a, something i'll hold up my hand and admit to. and it was one of the joys of doing the film was seeing how poorly men age and how wise women are. wheras we, it's not even like we think we're living in the past. we just are, and we're not admitting it to ourselves for so long. >> reporter: the new film is a sequel to the 1996 original "trainspotting," about four heroin-using, small-crime committing, wild-living young men. based on a 1993 novel by irvine welsh, it was a low-budget affair, boyle's second feature film, with then little-known actors, that became a smash hit. one of the most successful films ever made in britain, with a large, almost cult-ish following in the u.s. and worldwide. >> we believed in it very fervently, very passionately, in the book and how w