Some mornings, he would fall into the building and make his way to a desk hoping nobody smelt his breath. This was the same Denzel Washington who later won an Oscar for his stirring performance in the Civil War epic Glory. The same actor who so convincingly played South African civil rights leader Steve Biko in Cry Freedom.
But before he found his calling he was on the slippery path to nowhereland. Before the post office job, he had collected trash and worked for the sanitary department in Mt Vernon, New York. The preacher's son had reached the end of the line. It was either get up and get out or go the way of the bad guys on the block. "I was inches away from alcoholism and I knew it.
"I was a lost soul. While others were getting on with their lives I was doing everything in my power to shorten mine. But something, or somebody, made me want to drag myself back from the brink."
Washington almost flunked out of his course at Fordham University. "But the dean was a kind, thoughtful man. He told me to take a period off to get my mind right. I went to summer school where somebody convinced me to climb on to a stage and do a little routine for the kids. This guy who'd been a friend to me said, `Man ... you're a natural.'
"I didn't need much convincing. The answer was right there before my very eyes. What I had been searching for."
When Washington returned to university he switched to a drama course. His dream was born. But he grins as he says: "The second play I did was a musical and you know what? I found out I couldn't sing at all."
Now in his forties, the acclaimed actor is the father of four children and has been happily married for 15 years. Tall and lean, he is also very laid back. "There is no secret," he says softly, when you wonder how he does it - the marriage, the career.
"The reason I keep control is because I am not the reason the sun comes up in the morning. I am just glad it comes up.
"Of course, I thought I was special when I was a teenager. But I am happy knowing I didn't have to step on toes or stab people in the back in order to get on. I'm also not on a big ego trip. That in itself is the biggest load off my shoulders.
"You can be decent and win. I try to tell my kids, `Look at me ... give it a try.' I am going through this thing with my eldest boy right now because he just wants to hear rap music.
"So I say, `OK, this is what we will do. You can hear this stuff but we have to hear it together. Then let's talk about it. `He's almost 14 and he says I am way behind. Other parents let their kids be cool.
"I said the same thing to my mother when I was 15 and she said I had to be home by 9pm. I thought her goal in life was to destroy me. I was this square; I couldn't be hip. I'd go around thinking, `What is wrong with her?'"
After a pause and a sip of water he adds: "You know what? Two of my friends are dead. One of them was shot and murdered. The other died from Aids which was related to drugs abuse.
"I have another friend from my earlier years who is doing life and another is doing 15 to 25. All of those guys thought they were hipper than me.
"I now understand what she was doing for me then. So I tell my kids, `You may not understand but this will pay off for you in 20 years.' "
Washington's father was a Pentecostal preacher. His mother, Ellie, was born in Georgia and raised in Harlem. They divorced when Denzel was 14, and he was emotionally wrecked by the break-up. "I thought, `How can this be?' So at about 14 or 15 I started fighting. That had a bad effect, but I came around.
"It is a long journey. We are all human. I waver. I want to do the right thing but I'm no saint."
Washington first rose to fame on the small screen, as Dr Philip Chandler in the hospital series St Elsewhere. He has been at the top for well over a decade now, and commands a minimum pounds 10m a movie. He is probably better known for his "serious issue" parts and his roles in several Spike Lee films.
The subject of Washington's latest film, Fallen, is not one that everyone will take seriously, but Washington certainly does.
He plays John Hobbes, a policeman who has a devil of a time getting to grips with some very weird goings-on. At each of a series of motiveless brutal slayings, onlookers are seen touching each other strangely on the shoulder and whistling the Rolling Stones song "Time Is on My Side". Hobbes discovers no one can be trusted, even his police colleagues, and the case becomes a struggle to the death against the forces of evil.
A religious conception of evil is a subject that is close to Washington's heart. "I believe in God and I am a positive person. It's no coincidence that films like this are being made more and more and there is talk about God, evil and the devil. People are looking around and seeing what hasn't worked. They see floods, earthquakes and disasters and they question.
"I have never come across real evil," he says. "I was bullied when I was a kid, but I believe in good; I think good is power over evil. When you buy into evil you give it fuel and evil is fuelled by fear. If there is a devil that is how the devil operates. Not by touching you or making you sing Rolling Stones songs.
"I am at a place now where I look at the world and the abilities I have been blessed with and I can't afford to sit around and not talk about what I believe," he says earnestly. "I look at this film as an opportunity to do that, as a springboard. People need to hear it, not from me maybe, but they need to hear it. The metaphor for this film is, `What are you doing for others?'
"But I don't see me as a role role. Did I ring Sidney Poitier up when I was 12 for a chat if things weren't working out? I don't think so. Nobody is winning or losing. Are they?"
`Fallen' opens todayReuse content