Since 2012, David Sawyer has been on a journey, which has led him – halfway through – to reset his life.

He has just written a book about it, drawing on his family’s experience and those of hundreds of Nobel prize-winners, academics, athletes, self-help authors and philosophers, to chart a route for midlife professionals to take stock of their lives and, within a year, transform their futures.

Here are his top 12 tips on how to live long and prosper – without the shackles of work.

1 Find what matters to you

Life’s about being happy, right? Well, if it were as simple as that we’d all be eating junk food, watching telly and glued to our phones. What we’re really chasing is that meaningful happiness that comes through our accomplishments, our world view and our relationships.

People on their deathbeds regret unfulfilled dreams, missing their kids growing up, working too hard, not saying what they thought, not spending enough time nurturing friendships and not realising there is another way. Don’t be those people. Decide on a clear vision of where you want to be when you don’t have to work for a living anymore (mine involves Andalusia), and work out what exactly you’re going to do to get there. A measurable family mission statement pinned on the corkboard works well.

2 Realise nobody really cares about you

Apart from your close friends and family, people only care what they can get out of you. It's a harsh and uncomfortable truth but the world owes you nothing. If you give them something that's valuable to them, that's where the gold lies. If you don’t believe me, I recommend you watch the Alex Baldwin speech in Glengarry Glen Ross. Seize the day: whatever you're doing, show the world what you've got.

3 Go digital to future-proof your life

For many midlife professionals, going digital has become a work-stick to beat us with, as we fight to juggle the competing priorities of our lives. But working away to increase your digital profile is one of the best ways to enhance your career prospects. So, read blogs, set up your own, start an email list. Read, commit to lifelong learning ... have a dabble for Pete’s sake. Taking advantage of the amazing opportunities the internet brings could be your happiness-at-work pill, escape plan, ticket to promotion and/or insurance policy. Long-term, it’ll help your money, and your life.

4 Declutter

One of the best ways to do meaningful work, accomplish things and generally make yourself happy is decluttering your life: digitally, mentally and physically. Turn off your notifications, charge your phone overnight anywhere but your bedroom and wean yourself off those dirty dopamine hits (Ding: somebody wants me, somebody likes me. Give. Me. That. Phone). Be mindful, offload on a friend, try, like millions of people the world over, Julia Cameron’s Morning Pages. But most of all, declutter your house. Trust me, there’s a life-changing magic in tidying.

5 We’re rolling in it

As midlifers who always feel skint, it’s hard to believe we’re rolling in it. Say you’re a primary teacher in Scotland with a few years under your belt, on £30k. That turns into £23,780 after tax. Did you know that places you in the top 1.18 per cent richest people in the world? Or how about the findings of Danko and Stanley in their unrivalled The Millionaire Next Door? Many people they interviewed with a net worth of $2 million or even $3m got there on a joint pre-tax annual household income of $80,000 (£56,000).

Our best chance of financial independence or early retirement is not winning the lottery, it’s protecting the money we have and making it work harder for us. Achieving financial independence is within our grasp. We just need shown the way.

6 Do your stash maths

The biggest thing holding back financial freedom in Scotland is fear of the morass of pensions, shares, windfalls and long-dead great aunty inheritances that comprise most people’s financial future until, in their mid-fifties, often too late, they realise they better start thinking about these things. All this becomes simpler when you do your “stash” maths, a term coined by financial independence guru Mr Money Mustache (aka Pete Adeney). Establish how much you need to live when you retire (I prefer to think of it as when I achieve financial independence – never having to work for money again). Find what you’ll need to draw on when you get there. See what you already have. Then – based on stash-size required, frugality/efficiency of your family, target financial independence date, budget – identify how much you need to save every month.

It’s not as simple as all that (the methodology is fully explained in my book), but working out these figures with your partner is fundamental to resetting your family’s life, and will show you just how possible this dream is.

7 Budgeting

No-one runs a business without doing the numbers once in a while, so why is it so difficult in our personal lives? Last year I calculated that every latte I buy adds 10 minutes on to my working week; I drink a lot less coffee now. Let’s get something straight: this is not an anti-work manifesto. I love my job. But I’d much rather be doing it because I want to, not because, like most people, I need the money.

Budgeting is easy. Use Money Dashboard and a spreadsheet (I use Martin Lewis’s Budget Planner). Like Rich Dad Poor Dad author Robert Kiyosaki, track every pound – in and out – and you’ll soon be marvelling at your previous twice-weekly meals out at the kid-friendly posh café, because you were too worn out from your day’s work to go home and cook your family a nutritious meal.

8 Frugality/efficiency

I’m a PR consultant, my wife’s a social work manager. We live comfortably in an upmarket suburb of Glasgow. Partway through resetting our lives, we slashed £900 off our monthly spending. We allocated an extra £100 to our holiday pot, and invest the rest, simply and wisely. We’re not living on mung beans: we both work full-time, holiday six weeks every year and spend more precious hours with our kids. This makes us happier. Efficiency is a mindset and once you reset, people who drive Range Rover Evoques will cease to provoke feelings of envy. Embracing efficiency will run through your life like a sinuous muscle, affecting everything from where you put your shoes when you get in from work to where you shop. I recommend The LAHs (Lidl, Aldi and Home Bargains).

As midlife professionals we have little time. Being efficient helps us make the most of it, and find lots more.

9 Indexing

What to do with your developing stash? Consider investing in a globally diversified portfolio of super-low-cost index funds and ETFs (within your work defined contribution pension or consolidate in your own SIPP(s), when it comes to workplaces you left long ago). If you must have a dabble – some people are only human – never invest more than five per cent of your stash in individual shares.

Last, always keep a disaster fund (accessible money, eg, in ISAs) that will cover at least six months of family living expenses. And, it goes without saying, make your only debt your mortgage.

10 Secure your legacy

Sort your life insurance, make a will, set up a Power of Attorney and ensuring your partner is the beneficiary of any big money pots you have. Teach your kids your new savvy ways.

Did you know that a couple can pass on up to £1m to their children tax-free (assuming part of that inheritance is your one main home) when the last man/woman standing dies? If you commit now to getting rich slowly, your kids will be set for life at an age (averaging 61) when they have time to enjoy it.

Crucially, there’s usually one partner who does the money and one who has absolutely no interest in all things investments. Make sure you take a leaf out of Berkshire Hathaway owner and famed investor Warren Buffett’s book and, on your death (that will again), transfer your stash into something that doesn’t need any manual intervention from the surviving spouse.

11 Live a principled life

We are all different - the world would be a depressingly boring place if we weren't. However, if the past six years of experimentation and research for my book have taught me anything, it’s that there are common principles to living a good, meaningful and happy life. So, never give a monkey’s what other people think about you, make time for undistracted purposeful work, follow boring routines to be creative, work hard, act on enthusiasm and see where it takes you. Use negative motivation to propel yourself and find somewhere you can test your developing worldview to see whether what you believe actually works (my experimentation ground is running).

12 Don't be a stranger

Does all this sounds too hard? Do you just want to continue along the path you’re on? Well, it turns out the strongest predictor of how long you’ll live is your daily interactions with strangers. Not the quality of your close relationships (albeit that’s a close second), not whether you smoke, drink, exercise or are fat or thin.

In a meta-analysis of 300,000-plus people, researchers at Brigham Young University found that the key to living a long life is social integration. Those chats with your neighbours, people at the school gate, the bloke serving you coffee at Starbucks, the guard on the train; it’s those daily interactions on which we place no emphasis that make for a long life: how much, and with what positivity, you interact with people who don’t mean a great deal to you as you move through your day.

And finally...

Resetting your life can be as long or short or complicated as you want, but do, please, consider it. Never, ever, despite your outwardly successful appearance, accept that the hopes and dreams you had as a kid are gone forever. Never accept that this is it, and just live for your family.

It is never too late to reset, even without the external force that commonly prompts a reassessment of what we were put on this earth to be.

Last, I leave you with William Ernest Henley’s fine words in Invictus: “It matters not how strait the gate, or charged with punishments the scroll.

"You are the master of your fate. You are the captain of your soul."

:: A version of this article first appeared on UK investing blog Monevator.

:: David Sawyer (45) works in PR. He is a 2:40 marathoner (Berlin, September 2017) and lives on the south side of Glasgow with his wife, Rachel, young kids (Zak and Jude) and pet – Hamsterdam. His new book, RESET: How to Restart Your Life and get F.U. Money (The Unconventional Early Retirement Plan for Midlife Careerists Who Want to Be Happy), is available on Amazon. The Kindle version costs £2.95; the paperback costs £10.95.