I had a great time during my three and a half years in Her Majesty’s Estate. Yes; I was sad not to spend the holidays with my loved ones. But I get the most satisfaction - indeed happiness - in cheering other people up. People said I was “putting a brave face on it”. No I wasn’t. There’s not a lot I could do about my face. I really did find my entire time a totally rewarding experience.

Don’t misunderstand me. I’m no saint. Indeed, I probably have more faults than most people. But I do find it incredibly satisfying making people smile. Anyone who has heard my music may find this hard to believe and will say the general reaction from most sensitive souls is at best to block their ears and at worst to vomit. Leap Up And Down Wave Your Knickers In The Air may not be Rachmaninov. Una Paloma Blanca is not even George Michael. I have met some people who admit to liking The Sun Has Got His Hat On and even Who Let The Dogs Out? Although, during my time behind bars, I sometimes felt I Get Knocked Down But I Get Up Again was more appropriate.

Matthew Parris quoted my song Everyone’s Gone To The Moon in the Times a few weeks ago. “Eyes Full Of Sorrow, Never Wet”. I was a teenager when I wrote and recorded that in 1965 - it illustrates politicians today whose “thoughts and prayers are with family and friends” but who actually don’t care at all. “Hands Full Of Money - All In Debt”. Yes; very 2017.

One fellow inmate tended to get picked on. He confided in me that the worst thing about his time inside was that, every time fried eggs were on the menu, servers made sure the yolks of his meal were broken. He hated it; they knew it; and they got amusement by annoying him. I had a word with my friends behind the counters and asked them to stop doing it. They did. A few days later he came into my cell, almost weeping with gratitude. It wasn’t just because his eggs weren’t broken any more; it was because someone, almost a total stranger, had listened to his silly worry and cared enough to do something about it.

It made me happy to have made him happy. And the servers, who felt good helping me, as in other times I had helped them. Everybody benefitted.

Now you might think this is possibly the stupidest Christmas story you have ever heard. But the reason I tell it is because, if you want to have a really great Christmas, I urge you to try to make one unhappy inmate a bit happier. You will be astonished how good that will make you feel.

Not just other prisoners; screws and staff need cheering up too. The guy in Healthcare may have problems. The chaplain may be depressed.

A rather unpleasant screw in Belmarsh once said to me “King, why are you always smiling? You’re not meant to be enjoying yourself. You’re meant to be miserable”. I replied “I would be if I had to work here”. Credit where due, he laughed as much as everyone else.

December has always been a good month for me. My birthday is followed by Christmas and then New Year’s Eve. I had so many cards from people, both outside and in, that my cells looked like Aladdin’s Cave. Four Christmases inside - colourful and sparkling.

My attitude to life is - make the best of it. I don’t like being ill but if I am ill, I enjoy the benefits of being in bed or getting looked after. I didn’t want to be in jail but as I was, I vowed to have as good a time as possible and one of the silver linings was that there were a lot of unhappy people who I could cheer up a bit.

Mainly (and those who know me will laugh) by listening. Listeners often told me I was the best unofficial listener they knew. Chaplains often sent people with problems to talk to me. Because I’ve always been fascinated by people and have enjoyed hearing about their lives, the good and the bad, and suggesting ways of improving their quality of life. I was horrified by the amount of people who could not read nor write, and naturally I wrote letters for them and read correspondence to them. I helped twelve people get their appeals heard, and granted, by perusing their legal papers.

One of the great things about prison was that it increased my tolerance and my patience. I’ve always known that there are people who have done terrible things but who can be witty, nice, interesting and kind as well. I cannot stand the increasing superficiality of people these days, when 140 characters is sufficient for most topics and friends are often people you’ve never even met. Human beings are complex and endlessly intriguing. The media and our broken judicial system like painting people as one extreme or the other. But the truth is that we are all in between, some good, some bad, most average.

I joked that criminals were morally far superior to the characters I had mixed with outside - mostly media and show business types; many journalists, politicians and even police. I read an excellent piece recently about behaviour in prisons, and how easily inmates can turn on you, but I found the opposite; when you’re locked up with people, you and they tend to be more polite, better mannered, less rude. I made many good friends inside and found something to like in almost everyone.

Write to somebody in prison. Phone somebody. If you're in prison, listen to somebody. At very least, just hear them. Show them they can trust you. Give them advice. Hear their stories. Help them heal their pain.

Anybody can do it; you just have to want to. So this Christmas find someone who is really depressed and try to cheer them up. Not only will it help them but it will be the best Christmas present you could ever receive - from yourself.