It is a silence that has permeated our collective memories in the generations since that day.

But, when first it struck, it was so radically different from the sounds that had greeted our Australian and New Zealander relatives when they first reached the battlefield on April 25, 1915.

Now, a century after the guns have stopped, and a decade after Australia's last digger died, the silence is almost unfathomable.

We, the generations who have lived in relative peace from birth, may find it hard to picture what a world at war might look like.

Though the tales are widely known, translated, disseminated and inherited from generation to generation - and rightfully so.

No-one alive today could truly know what it felt like to traverse the metres of Gallipoli Cove under heavy gunfire.

Our heroes, our diggers, no longer walk among us.

While they were with us, they created that tangible link to history.

In those days, our Anzac Day commemorations paid respect to their service and their sacrifice.

Now that they are gone, the respect remains.

But, our observance has taken on another vital function in their absence. That of remembrance.

Now, we might only know the stories. We might only see the photographs, tinted and creased by history.

Saturated they might be at this time of year, they have become so much more important now than they ever were.

Now, that is our record of a world we can hardly fathom and can no longer recognise.

On Thursday, when the final refrain of the Last Post shall reach our ears, every service in every town or city across this nation will be punctuated by three words, spoken in unison: Lest we forget.

Lest indeed. For if we do lose that memory, we run the risk of repeating an unspeakable, painful history.

And that might be the greatest tragedy.