Aroma therapy: Why do certain smells make us homesick?

My father would travel a lot when I was a child. He worked, over the years, as a travelling salesman, to make it sound exotic, selling things such as paper towels and napkins for Bowater-Scott and, for the best part of my childhood, selling cigarettes for Phillip Morris.

My childhood was built on being able to make fancy swans out of paper that you could insert into cocktail glasses at dinner parties, and Marlboro Red.

When he was away I have clear memories of hiding away in his wardrobe. Nothing was built-in in the 1970s. He and my mother had their own veneer free-standing pair, two hanging areas, with a set of shelves in the middle. Separate like their lives were, in retrospect.

My parents divorced 20-odd years before dad died. When he did, and I acknowledge my sister did all of the work, we went through those wardrobes, each item, each memory, sorted into a different bag. Keep or not.

The wardrobes were mission brown, cheap looking, not very stable. But they were full of things that made up his life. We found football programs, his life membership badges, so many ties, the club blazer we buried him in.

I remember, years before, as an inquisitive teenager, finding a copy of D.H. Lawrence's Lady Chatterley's Lover in the drawers, alongside old copies of Melbourne's Truth newspaper (which he only ever bought for the race guide). Why dad, why?

I can't remember ever seeing my father with a book in his hands his entire life. I told him, when I was due to give birth to my son, that I would name said son Thomas Hardy (his name was Thomas, but everyone knew him as Curly) if he read Tess of the d'Urbervilles. My son is Joshua.

But the thing I remember most about that wardrobe was hiding away in it. His clothes, shoes, a samurai sword. Long story. And the smell of it. I would sit in the dark and just inhale that smell. The smell of my father. He was away, but he was still here.

That reaction has now been transferred. I've only been in my new home for a few years; my son has only spent a part of that time with me; but his room, at the back of my house, smells just like him. What is it about smelly boys? I come home, via the garage, and it's the smell that greets me. I am home. I inhale it. Draw it deep into my bones.

In her book Why Am I Like This? Dr Jen Martin talks about the role smell plays with our emotions.

"There are several theories as to why smell, memory and emotion are so tightly linked," she writes.

"A major clue comes from the fact the olfactory bulb (the part of the brain responsible for processing information about smells) and the amygdala and hippocampus (regions of the brain associated with processing emotion and storing long-term memories respectively) are all located close to one another. Recent research even suggests some long-term memories might be stored in part of the olfactory bulb."

There are smells that remind me of my mother too. She was a hairdresser. I am still able to differentiate between types of hairsprays. I can pick Schwarzkopf at 100 metres. Perm solution too. The biscuity smell of a good blow dry.

Martin says the research has shown our memories are most emotional when triggered by scents, as opposed to sounds or images.

"Hence the heart-wrenching pangs of homesickness when you smell something that immediately transports you back home," she writes.

"Smells are connected to memories by networks of nerves in our brains and it has been shown when we smell something during an emotional experience, that smell is neurally woven together with the memory in the same region of the brain.

"Once the link has initially formed, a distinct smell has an amazing capacity to trigger the associated memory for many years to come."

But why are our noses so sensitive?

"It's possible we evolved to be great at detecting smells for safety," says Martin.

"Scientists suggest our sense of smell may have been just as important as language in giving us modern humans an evolutionary leg up. It was a distinct advantage for our ancestors to be able to smell fire, tasty but hard-to-find food, or food that had gone off."

My sense of smell is all about love. I swear I could identify both my kids via my nose. My parents too. Maybe a lover or two who I could find in the dark just by the way they smell. Sea salt, sweat, desire.

Breathe it in.