REGIONAL – You only get one mother. And our relationship with her is formed during the most vulnerable, and in many ways most important time of our lives. Nothing else will shape us quite as much as how we get along with mum. And on Mother's Day, this Sunday, most of us will be thinking about this woman without whom we wouldn't exist. I know I will.

But while I can recall my family life, and many memories of my mother, there's another side to this... And it's one that may not really come alive to us until after she's gone. At that point, going through the papers, photographs and mementos of her life, many of us discover that other person, the woman and one-time girl, who became our mother. At that point things can get jarring. Who is this younger woman? What was she doing before I existed? There's that inherent selfishness of the child — our mother belongs to us as much as we belong to her so how could she have a life that didn't include us?

My own mum was of Irish ancestry on both sides of her family and grew up north of Boston in a town once famous for manufacturing shoes. Her father was a foreman at a big General Electric factory. Her mother kept house and managed three daughters. My mum was the middle one.

I already knew she was a fiery kid, that she was a Frank Sinatra fan from his early days, and that she was the protector of her little sister and an upstart in constant rebellion against her older sister. Her arrival strained the family budget and it seems my grandfather always held this against her. He was a hard man, it seems, in a time long before I knew him as lovable Grampy.

Mum grew up in the Depression, and like most of her generation she was deeply marked by those dark years. However, from the single picture I have of her from that time I see a girl with a happy smile.

She was a Catholic schoolgirl. The nuns tied her left hand behind her back to force her to learn to write right handed... a story I remember well from my own left handed efforts to write. I have her "devotional"— the "Key of Heaven" — given to her by her mother when she was 12 years old. It is well thumbed, and I treat it very carefully. But in later life she lapsed from the faith. Perhaps she would not have done that had she remained in the town, or the region, where she grew up, but that was not to be.

Could that girl in the black and white photo, Boston style apartment houses in the background, have imagined the life she was going to have? Did she ever dream she would spend most of her life on the other side of the ocean... not in Ireland, but in England?

This is the part of her life that I find most mysterious, and from which I have but a couple of photos and a few scraps of information that she let fall in unguarded moments. In the first picture, taken in her hometown, she's posing for her boyfriend seated on the bonnet of a car that looks quite enormous. She's a very attractive young woman with her skirt pulled down decorously, legs together, posing a little self-consciously for this young man that I never knew and whose name I only have from another photo — Mason Milligan. There are several pictures of them together, so I know this must have been a serious romance. Indeed, I have another clue about that...

But that relationship did not last. From those scraps that she let fall I know that they had a project. They were both working —she had a retail job, never discussed, and they were saving up. And then he did something foolish with the money. Whatever happened, she dumped him and the next thing was that she really showed him, and perhaps her father too, by moving to Buffalo. She took a job as a secretary there.

Today, perhaps, that wouldn't seem quite so unusual. But in 1941, it was a daring move for a young lady. And I can see her with her suitcase, wearing a sensible overcoat and a 1930's style hat, about to take the train from Boston, leaving home and going into a life that would go beyond anything she'd imagined before.

Because the war was just about to catch up with her. And that meant she moved again, this time to Washington, D.C. and a job in the War Department. She never talked to her children about that period other than to tell us about the all-weather Rubber Road project she worked on for the army in Alaska, in case the Japanese invaded.

But here are these guys — Don Flynn, a "newspaper man in Boston," and Mason again, and then this mysterious chap, Murray Patrick, from her home town who joined the Canadian Air Force and then the Royal Air Foece and sent this long letter from Egypt in 1942. He hadn't written in a while, he notes, because he'd heard she was getting married to that Milligan bloke. But this letter, sent via Pan American Airways "system," included a photo of the great pyramid and she kept it very carefully. It obviously meant something to her.

Going through old photos, old letters, and items carefully kept throughout the life that came later and brought my father into the picture, and then me and later my brother, I have this curious sense of piecing together someone's life who was not my mother. I almost feel I'm invading her privacy. She never spoke about these young men, but she kept their photos and letters. Did she intend for me to see them? They are a part of her life, even if it's not the life she shared with me?

But then the first photos show up of her with my father, and maybe this is weird but I get a sense of relief. I am going to exist. They will get married and I will be born. And this young lady in the 1940s will become my mother, with whom I will have a long and sometimes stormy relationship all the way to her death.

And even afterwards as I become the one left to go through her papers and photos... and try to imagine her life before she became my mum.