If you’re anything like me, you’ll spend a day or two thinking about and then writing a column and still find yourself sitting in a bar in the middle of Liverpool at 9 p.m. on the night when you’ve already missed your intended deadline because you’ve had a sudden change of heart. And you also find yourself angry. And I mean really angry.

They always say “write about what you know” and what I know is that I’ve just come out of the art cinema, here in Liverpool’s FACT, after watching Tish, a new documentary about the British social realist photographer, Tish Murtha. And as much as I should sit and finish the 800 words I’d already written, I can only think about Tish. Everything is about Tish. It’s a film that hit me hard and I know I’ll never stop thinking about Tish in one way or another. I’ve watched nearly 350 films this year and none have affected me this strongly. It’s changed how I think, which is perhaps the highest compliment you can ever give a documentary.