It was during the Crimean War that Florence Nightingale, the founder of modern nursing, first rose to prominence. She was then in her 30s, and by the time she died, aged 90, in 1910, very few of the soldiers she nursed in that conflict were still alive.

The only Crimea veteran to attend Nightingale’s funeral was Private John Kneller from the Royal Welsh Fusiliers. He lost an eye in the siege of Sebastopol, and was sent to the military hospital at Scutari in modern-day Turkey, where Nightingale worked.

Newspaper reports of the funeral describe the the old soldier as a “pathetic figure”, “very frail” who “walked painfully”, and yet was full of praise for the woman who had ministered to his needs more than half a century earlier.

“Every night,” the Western Gazette quotes Kneller as saying, “she came through the hospital with a lamp when the medical officers had left us. We tried to keep awake so that we could see her.” He had come to the funeral, he told his fellow mourners, to fulfil one wish: “to pray at the graveside that heaven would reward her.”

We can all learn from John Kneller. Our lives are so busy that we don’t spend nearly enough time being grateful and thanking others for what they do for us.

There’s plenty of academic evidence that gratitude is good for our mental health and wellbeing. Couples who thank each other regularly have happier relationships, and grateful people are also considered warmer and friendlier.

Another study demonstrates the benefits of putting our gratitude in writing. Researchers randomly assigned 300 adults with mental issues to three groups. One of the groups was given counselling, one was asked to write about negative experiences, and the other was asked to write one letter of gratitude to another person every week.

It was those in the third group who reported the biggest improvement in their mental health. Encouragingly, the positive effects of writing “gratitude letters” also increased over time.

So, why I am telling you this? After all, this is a blog for a financial planning firm. What has gratitude got to do with that?

Gratitude is, in fact, hugely relevant in a financial planning context. Financial planning is all about working out what makes you happy, and what a life of fulfilment looks like. Many people, perhaps even most people, don’t even stop to consider those very important questions.

Even among those who have considered them, there are many who haven’t discussed the issues with a third party. The problem is, we have self-limiting beliefs and commonly make false assumptions; what we tell ourselves will make us happy and what will really make us happy are often two very different things. That’s one of the reasons why working with a financial planner is such a valuable exercise.

Our experience as a firm is that when people properly confront these issues, they often realise they don’t need as much money as they thought they did to lead a happy life. The most rewarding conversations we have with clients are those in which we can tell them that, if they want to, they can retire two, three or even five years before they thought they would have to. In some cases they don’t even need to work another day longer.

Sure, early retirement might not be for you. But you really don’t know until you understand yourself and what it is you want from life. How do you go about doing it? Well, practising gratitude is an excellent way to start.

If you sit down and write a list of all things that you’re thankful for, you’ll be surprised at quite how long it is. Something that I’ve started to do myself is to keep a gratitude journal. Every night I try write down three things I’m grateful for before I go to bed.

Another thing we’ve noticed as a firm is that when people start thinking along these lines is, they often realise that a happy life is much less dependent on material possessions than they previously thought. In almost every case, it’s more about experiences and relationships — doing what they want to do and spending time with friends and family.

No, there’s nothing wrong with wanting “stuff”, perhaps a bigger house or a new car. But will it be money well spent? How much happier, if at all, will it actually make you?

So, go on, give it a try. Develop an attitude of gratitude, and focus on what you do have instead of what you don’t. Yes, John Kneller lost an eye, but he survived one of the bloodiest conflicts in modern history. Nearly a million troops who fought in the Crimea didn’t. Thanks to the medical and nursing care he received, he enjoyed another 62 years of life.

By the way, Kneller’s show of gratitude to Florence Nightingale didn’t go unnoticed. When he himself died seven years later he was buried with full military honours and his own funeral received national press attention.

Kneller is, of course, just a footnote in the history books. I only know of him because he’s a distant relative of mine and my brother came across his story while researching our family history.

But he taught us an important lesson. It really does pay to be grateful.

Robin Powell is an award-winning journalist and RockWealth’s Head of Client Education. He blogs at The Evidence-Based Investor.