He made his career by recalling, and replicating, the characteristics of celebrities and last year exorcised the memory of Jimmy Savile for many with his critically acclaimed portrayal of the sex abuser on stage.

Now Alistair McGowan is back at Park Theatre in 4000 Days tasked with playing a man who has awoken from a coma and forgotten the last decade of his life. His character Michael remembers nothing of his partner Paul, who must fight to bring Michael’s memory back, while Michael’s mother Carol fights to remove him from their lives completely.

Alistair, 51, who was born in Evesham and lives in Hammersmith took a break from touring with Jasper Carrott to talk about the nature of memory and share some of his most important ones...

On the power of memory...

People do lose their memories. It must be very scary. We are all very aware of diseases like Alzheimer’s now and memory loss is a very big part of that and dementia. I think it is something we probably all fear because memories are so important. As much as nowadays we seem to want to preserve everything with photographs and selfies I’m sure people still look back and think ‘I don’t remember being there’. Memory is very comforting and important. It can sometimes be very destructive if they are bad memories. The whole idea of memory has always fascinated me.

If you had the choice of remembering or forgetting everything...

Remember everything of course. I read somewhere years ago that we don’t forget anything, we just can’t always recall it and I think that’s true. Last night I met someone from my past that I hadn’t seen for 30 years and they showed me some photos I had never seen and while I couldn’t remember that person I could remember that person and that room and suddenly it came back. There was a wonderful programme which took people who had been famous in the '70s and weren’t well now and they took them into rooms decorated with '70s things and they suddenly came out of their depressions because they were reminded of that time when they were happy.

Your happiest memories...

I had a very happy childhood. We weren’t superbly well-off and I was privately educated but it was just the four of us and I always remember everything with great happiness. I lost my father ten years ago but I have so many fond memories and I think it’s why I take such an interest in football (he supports Leeds United) because it reminds me of him and fond memories of going to matches together and that’s invaluable to me.

My mother was an amateur actress and involved in a local society so she got me going with performing. She used to do lots of impressions of people she worked with, she was a teacher so used to do impressions of teachers and parents and even pupils. Teatimes were always entertainment as we’d ask ‘what happened at school today?’ and there would be endless stories. So it was encouraged without them really saying it.

That first time on stage...

The first play I did was at school and I still remember the fear and terror. And I remember I was learning guitar when I was about 11 and had to sing Molly Malone at the end of year little concert in front of the whole school and I can still remember sitting down and being terrified of singing that dreadful song. I remember singing it really poorly and noticing that when you are nervous is goes to your voice. I have always remembered that when you are in this business you have to be so confident because otherwise it does go to your voice. I have started playing the piano and was asked to play in a celebrity concert a few weeks ago and noticed my hands were shaking. So it goes to my voice when I’m singing and hands when I‘m playing the piano.

The worst thing he has forgotten...

You want to put bad things to the back of your mind and convince yourself they never happened and I have done that once or twice. I remember a few bad experiences in show business. I had an awful time on Mock the Week which I have tried to forget about. And a show with Ant and Dec I did back when they had just started presenting a children’s show, I had an awful day and every time I see them I get reminded. It didn’t affect my career or ruin my life and they are very nice boys but I just felt I was in the wrong place at the wrong time and that’s never nice especially when it’s being filmed.

On playing Savile...

It was an extraordinary experience. We had no idea if it would be successful and there was so much controversy which I had tried to stay away from because I don’t Tweet or really do anything on the internet.

The first night my mouth was absolutely dry. I didn’t know if people would boo or throw things at me or punch me and in the end they were just silent which was worse initially. I thought ‘why aren’t you responding?’ but they were as terrified as us – they didn’t know what they were going to see.

But the moment it started people realised it wasn’t sensationalist but an exploration of how he got away with what he got away with. Then it became a hot ticket which was a new experience for me. I have had things that have done well but to be in a show that was being talked about in the papers and people clamouring to get a seat was really exciting. But we were always aware of what a serious issue it was and we had a lot of people wanting to talk about the issues afterwards and use words like cathartic and saying seeing the play was some sort of closure.

We could see we had affected people every night. People said it was an experience. And it was. It was almost something other than a trip to the theatre.

Enfield Independent:

Memories of Finsbury Park...

It’s miles from where I live in Hammersmith but I’m looking forward to the chocolate brownies in the bar which are sensational and the ‘nana banana’ man by the station. I froze some strawberries last time I was there so I still have a little bit of Finsbury Park in my freezer.

On how he first became interested in the environment...

When I was just out of being a student in 1989 I was reading article about us running out of resources.

I shop locally and avoid supermarkets and walk as much as I can, its much healthier and I try not to take planes.

I used to want to change everyone’s attitudes but after a while you realise you are banging your head against a brick wall. The message has been put out there for 20 years but some people don’t seem to hear it at all.

There is a brilliant proverb from Hopi Indians ‘Only after the last tree has been cut down, only after the last river has been poisoned, only after the last fish has been caught, only then will you find that money cannot be eaten.’ I read that 20 years ago and thought ‘wow that’s true’. George Osbourne is evil environmentally. He just doesn’t get it and thinks as long as we are all making money we’re OK. But at what cost? There comes a point where nature hits back and we are seeing it more and more in Cumbria and each year and of course it’s no coincidence.

At one time I wanted to do everything and make documentaries and shout from the rooftops but I can’t any more it just depresses me too much to think how wilful people are and as far as I can see the majority of their priorities are wrong.

On the future...

I’m writing a play for Radio 4 about a classical composer and pianist which will be on in the spring and I’m writing a show for the Edinburgh Festival about a different classical composer Erik Satie with the aim of performing as well. He wrote some really witty and unusual and surreal music and some strange words which he never performed. They were addresses to people about what he felt strongly about so the plan is to perform those. It’s something I’ve been meaning to do for years and now it’s suddenly fallen into place.

4000 Days is at Park Theatre, Clifton Terrace, Finsbury Park from January 14 to February 13. Details: 0207 8706876, parktheatre.co.uk