Art teachers. They're always a bit different, aren't they? History teachers, geography teachers - conventional, right? Art teachers - totally not.
Mr Bagshaw, my art teacher at Ruffwood Comprehensive, contributed to my career in no small part. He made us all believe that no matter where we were from, no matter our background, with a little bit of training and knowledge and belief we could do anything: the possibilities were endless. That's not a common trait in teachers, I don't think. Certainly not in my day.
This sums up Mr Bagshaw: when kids misbehaved they were sent to the headteacher, and if the head thought they had behaved really badly he'd send them to Mr Bagshaw's class. You would be sitting in his art lesson and a troop of older kids would trudge in and stand at the back of the class. They wouldn't get a bollocking, no sir. That wasn't Mr Bagshaw's way. Calm as anything, he'd ask them, "What happened? What were you playing at, doing that? Why did you hit him? Well, that's no way to react, is it? You're better than that."
The kids would be gutted that they had let Mr Bagshaw down. He didn't raise his voice, he just exercised the timeless "I'm not angry, I'm disappointed" angle. It worked. Kids respected him and they hated letting him down.
He had this unwavering ability to instil self-belief in his students. I got an A in my art GCSE and I'll tell you how. I'd been visiting Tate Liverpool and trying to imitate that sort of work, but Mr Bagshaw took me aside and advised me to take a completely different route. "Use something from everyday life," he said.
Days later, I was running across the road on my way to school when I looked down and saw there were yellow grid lines on the floor, like a box junction. Using plaster of Paris and stones, I recreated a segment of that road; I called it Morning because I crossed that stretch of tarmac every day. I got an A because Mr Bagshaw had me thinking differently; I was playing to what I knew, not to what I thought people would want to see.
He was such an influential man. He was well-read and well-versed but he never had any pomposity or arrogance about him. And he never talked down to you.
He listened. I think that's where teachers can sometimes go wrong. Not listening to students is an error. "Listen to people" is a pretty important life lesson; I learned it from Mr Bagshaw.
But, more than that, he introduced me to Expressionism. To Salvador Dal. He taught me about Turner and Picasso; he opened doors for me and opened my mind culturally.
Alongside my parents, Mr Bagshaw has played a huge role in my career. A great man.
Stephen Graham was talking to Tom Cullen
You can call me Al
Born 3 August 1973, Kirkby, near Liverpool
Education Ruffwood Comprehensive, Kirkby
Career Played Al Capone in the HBO series Boardwalk Empire (pictured, far left). Has starred in films such as This Is England, Tinker Tailor Soldier Spy, The Damned United and Pirates of the Caribbean: On Stranger Tides