Something strange is happening to me.

Snatches of songs from 20 years ago have been humming in my brain.

For one whole day this week, my heart and mind beat to Dan Hill's 1977 hit single:

'Sometimes when we touch, the honesty's too much, and I want to close my eyes and hide.

'I want to hold you till I die, until we both break down and cry, I want to hold you till the fear in me subsides...'

Memories of people I once loved, or shared an uncommon communion with, flash back. I wonder how they are. Should I get in touch, or leave them be?

I scan my volumes of poetry. Each brings back memories. The Rilke I once so loved. The TS Eliot that still speaks to me. The Brian Patten that sings in plainsong of modern love.

I seem to be stuck in a time warp, re-living songs and poetry I loved 20 years ago, when I was young with the flush of youth.

I read eminent psychologist Carl Jung and I understand what is happening to me.

I am in the throes of midlife transition.

At the cusp of 40, my soul is telling me to stop and take stock. To trace back the pattern of my life to this point. To ponder life's eternal verities. To be true to myself.

And prepare for the next phase of my human odyssey.

Not many people know it, but midlife is considered one of the major transitions in life.

If they don't navigate this period well, they set themselves up for a miserable and disappointed old age.

Birth marks the first major life passage. Adolescence is next, when sweet kids turn into door-banging, rebellious monsters.

Then comes midlife as we transit from youth into the second phase of life. This usually takes place in the late 30s to late 50s.

The last passage marks the end of life, when we prepare for the final journey to death.

Midlife is considered a fairly modern concept. Life expectancy in 1775 in the United States was just 35. These days, better nutrition and health put life spans at around 80 in developed countries.

So at 40, one literally enters the middle phase of life, the period From Noon To Nightfall, to quote the title of an insightful book on midlife and ageing by M. D'apice.

This is a time to accept that we are beginning to age.

The body tells you so in no uncertain terms, anyway. Eyesight starts to deteriorate and you need reading glasses. Your hair thins and you wonder if you are less attractive. Late nights no longer give you an adrenaline charge; they give you a headache that lasts for three days.

The physical changes coincide with significant lifestyle challenges. Many of us in our 30s or 40s have responsibilities to our elders and children. Many are at the peak of their careers.

Family and work pressures pile on, at a time when you are mourning the loss of vigorous youth.

For some, the pressures mount up so much that a full-scale crisis erupts.

Otherwise steady people leave their jobs, their families, or change lifestyles totally.

But most people go through midlife trying to cope with the changes they feel in their bodies and psyches, accepting their limits.

Jung's theory is that in midlife, psychological needs repressed through one's growing up years force their way up to the surface of the conscious.

So if you had always wanted to be a mountaineer but got sucked into making a living, you may find yourself in your 40s or 50s valiantly attempting to scale Everest.

Maybe you always wanted to be a rock musician. At 50, you take up music lessons and rock to the dreams of your youth.

Some people respond to the fears of ageing by aggressive denial. This is what lies behind middle-aged men's sudden penchants for sweet young things, racy cars and flashy clothes. As the reality of ageing hits them, they rush into fantasy re-creations of swinging youth.

Psychologists advise that the best way to live through a midlife crisis is to accept one's fears about ageing, and journey inwards to discover what one really values. This way, the conscious and the repressed self can be integrated.

Denial only postpones the moment of reckoning.

One website www.thedisquiet.com has this advice for those going through a midlife crisis:

'You may think that it will go away by taking action - leaving your marriage or job for instance.

'But it's like eating lots of garlic and trying to hide it with mouthwash. The odor oozes out of your pores. Avoiding it just makes it come back smellier and messier.'

Psychologists advise facing up to one's real self.

This means spending time being alone, trying to figure out who you really are, stripped of the expectations of bosses and family.

What do you really value in life, when you remove social and external pressures?

For many, the answers will come from a gentle journeying back to early years, to a time before the weight of social and familial pressures constrains one.

For me, the songs and poetry are means to reflect on my life, to reach back through the layers of time, through the masks donned over the years, to a place where I am most myself.

It is an intensely private journey, that starts with the innocence of youth, to the flush of first loves, through lofty dreams and success, through failure and acceptance, lost illusions and shattered hopes.

In the process, we determine to live out some dreams, and choose to relinquish others.

Through it all is a process of integration: soul work that knits together who you are, with strands from who you were, into a strong soul's yarn, so you can become who you will be.

I experience a sense of discovery as I look back on my life choices. These are my Achilles' heels, the things that cause me to stumble. And these are my angel props, my tools through difficulties.

I experience elation when I discover that the spirit self stifled through years in the wilderness, lies welcoming still at the kernel of my being.

And most of all, to my surprise and wonder, through the sadness of lost dreams and the elation of discovery - through it all, a sense that, at the cusp of 40, I am returning home, to who I am meant to be.

This article was first published in The Sunday Times on June 1, 2008.