My Mentor: Alex Thomson On Geoffrey Lean

Geoffrey is the one grown-up, working journalist that I went to see when I was a student. This was in 1983 or 1984, well before the culture of work experience. I wrote to him, probably some appalling, brown-nosing stuff, then a reply came: "When do you want to come up? Here's the number, call me and we'll make an arrangement."

I've never forgotten that afternoon. He was probably quite young but he seemed impossibly sorted, effortless and graceful but gritty. This was a real journalist - he goes around and digs for stories, gets them and puts them in the newspaper. Mindblowing!

The conversation started in The Observer offices then went on in aLondon taxi. I'd never been inside Westminster and we walked into this gothic pile and saw Michael Heseltine and I thought: "Wow!"

But Geoffrey didn't present this as beautiful, glamorous work. He did present some very sensible advice: "Don't think you're going to be an environment correspondent. Don't think you're going to work on the nationals. Go away and get your knees under the desk of a local paper. Work your way up, win a few awards and see how it goes."

And I thought: "Christ, I can't even type!" It was grounding, knocking-the- scales-off-your-eyes advice. I remember seeing, behind the glamour of the byline or the TV studio, a very long and interesting, but actually much more prosaic career path.

When people write to me, I always say: "Come up and see me." Journalism is everything that most jobs are not - I'm presenting the Channel 4 News tonight and going to Afghanistan on Sunday - and it's very important to pass on what you know."

Alex Thomson is a presenter and chief correspondent for Channel 4 News