Casual smoking? Now there's a contradiction in terms. How anybody can open a box clearly marked "Smoking Kills!", remove the toxic substance, stick it in his mouth, light it and then "casually" inhale, is beyond me.

Certainly, I have been known to puff on the tobacco plant, but there's nothing casual about my smoking; neither is there anything casual about the film Smoke (1995).

Starring Harvey Keitel and William Hurt, directed by Wayne Wang of The Joy Luck Club fame, Smoke is not a universally popular film. Variety described it as "Plenty of smoke, not a great deal of fire". But for me it is a rare gem in which the narrative bends and twists around a series of unrelated short stories and characters whose lives are brought together only by chance and coincidence, a bit like real life - funny how the presentation of realism can appear surreal. Smoke simply observes the lives of customers who frequent a Brooklyn tobacconist. And in a strangely reassuring way, it has the tendency to remind us of a time when smoking in cinemas, buses and hospital wards was de rigueur, a time before cigarette manufacturers felt the need to inform us that we were, in effect, paying for a painfully slow death.

It is the sort of film that can set the brain thinking, and sent my mind spiralling right back to a time when I first met Joey Flynn, a fellow Corkonian. He was living in a place where stories mostly end; sleeping rough under the arches in London. And like many people nearing a destination, he was quite happy to recount how and where his odyssey began. I assumed he was a casualty of the 3D's - drink, drugs and depression - but no, not at all.

What began for Flynn as a penny fag outside the gates of the North Mon, and should have been a simple fleeting rite of passage, became a lifelong obsession.

Although large in stature, Flynn claimed he had hidden behind a cigarette throughout his teens. A casual smoker, indulging only when he so wished. Like so many before him, he could take them or leave them, until he decided to leave them - that's when he realised his "wish" was indeed, a need. The onset of maturity and the morning ritual of hocking up green bile copper-fastened Flynn's resolve to quit. So the battle lines between weed and need were drawn.

His initial strategies were typical to say the least; he would smoke a lower tar brand and only buy packs of 10. In theory this should cut down his consumption of tobacco to that of a casual smoker. It didn't work, thus proving that theory and practice are the same thing only in theory.

It dawned on Flynn that his reliance on tobacco was probably due to peer pressure and the vicious circle of lads, craic and pinting. So, he stopped going to the pub. Still smoking, he cut out his weekly visit to watch Cork City FC play. Every time star striker Pat Morley sent a pig skin squealing into the back of the onion sack, Flynn couldn't resist the urge to light up.

Realising that smoking went hand in hand with driving, Flynn took to walking to work. Of course, work had its own associations with the habit, so he gave up tea and coffee in an effort to avoid the canteen, and opted to stay at his desk, nibbling home-made sandwiches during lunchtime. Pay-day always brought on the desire, so eventually he gave up work altogether and just stayed at home.

The lingering residue of smoke around the house sat there like Satan on his shoulder, so with no alternative, he left home, and ultimately his wife and children whom he loved dearly. Isolated from friends, family and all things familiar, Flynn became a hermit. Life as he knew it just set off too many Pavlovian bells in his head. Still battling the weed, it occurred to him that maybe his addiction was due a subliminal oppression brought about by the slave mentality of his post-colonial Irish heritage, so that's why he moved to London. And that's where I met him, under the arches.

He asked me for a fag, I told him I was off them again. But I gave him three quid to buy a pack. He headed for the tobacconist. In the middle of the street he stopped, turned and with a big, broad smile shouted, "Doubt ya, boi!" raising his thumb in the air. I could do nothing but stand there watching, hopelessly helpless, as a passing coal truck just chewed up Flynn, splattering concrete and pavement with ex-smoker's blood and guts. I cradled him until the ambulance men prised his mangled body from my arms. "Smokeless fuel. . ." he whispered, as his eyes struggled for a final focus on the words printed on the side of the truck.

It's a commonly held belief that smoking one cigarette will almost inevitably lead to an other. Well, a similar phenomenon occurred during the filming of Smoke. Seemingly anecdotal chit-chat during rehearsal inspired director Wayne Wang to make a second film Blue in the Face, a modest budget, free style, improvised piece, set in the same tobacco shop. With Harvey Keitel staying on as head of the ensemble of actors - and the entire technical team held in place, Smoke finished shooting on a Friday, and Blue in the Face commenced production the following Monday.

While Smoke is memorable for its organic style, Blue in the Face probably fails because of its organic nature. The New Yorker magazine dismissed it as "pointless", despite its incredible cast including: Keitel, Madonna, Lou Reed, Roseanne, Michael J. Fox, Lily Tomlin and Jim Jarmouch.

I believe that Smoke and Blue in The Face work well as a companion set, but I'm sure many would say that, like Joey Flynn, Wang should have quit after the first one.

Conal Creedon's radio play, This Old Man He Played One, is to be broadcast on BBC World Service on Sunday at 1 a.m. and 5 p.m.