History isn’t really a thing of yesteryear.

It’s being made all the time, all around us, right in front of us, often without our notice. It informs and shapes us.

Sometimes the past meets the present in unforgettable ways, demanding that we sit up and take notice.

That we reflect. That we remember.

That we turn on to history.

It was certainly turned on this week...

Twenty-five years ago, on 9 November 1989, the Berlin Wall was breached by euphoric Berliners on both east and west sides, reuniting a city that had been divided for over thirty years. I was in New York’s Lower East Side when I heard the news. I was a student, so poor I could barely pay the rent much less board a last-minute plane bound for Germany.

So I joined the other merry-makers, dancing in the streets. Televisions were propped, facing out of windows so we could watch the goings on in Berlin. We wanted to feel more connected with all Berliners and their story, half of which we’d only been able guess at for years.

What I would have given to be on the Wall that day with a hammer in my hand, contributing to tearing down the barrier that had cast its cold shadow over society since before my birth! The world changed that day. You could feel hope reverberate around the globe. From Berlin to New York and everywhere in between, we were jubilant.

(And a dear friend, who happened to be there, returned with a little piece of Wall for me -- can you see it in the picture above?)

One hundred years ago, on 4 August 1914, long before I was born, humankind tasted quite a different cocktail of emotions. That's when Britain joined the Allied Forces, declaring war on Germany.

Some were eager to seize the call to arms, others were far less sure.

By 11 Nov 1918 – Armistice Day – 888,246 commonwealth soldiers had sacrificed their lives in the War to End all Wars, a war that would then be followed by a second World War, the Cold War, and the building of the Berlin Wall.

Last Sunday, while Berliners were preparing to celebrate the nighttime release of 8,000 white balloons, which had been set on 3.6-meter poles stretching for 15 kilometers to mimic the height and length of the wall, I found myself again wishing I could be there. Instead, I joined another peaceful, but more somber, crowd of thousands.

We met at the Tower of London to witness a most remarkable visual commemoration, marking the centenary of the outbreak of the First World War.

The installation, called Blood Swept Lands and Seas of Red, saw the creation and planting of 888,246 red ceramic poppies in the moat surrounding the iconic Tower.

The planting began on the anniversary of the day the guns of August compelled Britain to war. The last poppy, symbolizing the last commonwealth life lost, was planted today – at ten minutes before the 11th hour on the 11th day of the 11th month (GMT) – thus completing an extraordinary work of public art that's been embraced by millions.

The installation is simultaneously spectacular and sobering: Beautiful and hopeful, yet a metaphor for the fields of war awash in human blood.

The poppies, paid for by individual donations that raised money for six charities serving victims of war, were formed, fired, glazed, and planted by an army of 9,000 volunteers. They will now be removed and packed off to their purchasers by another 6,000.

Each poppy represents one fallen soldier. But to me, taken together, they represent the power of the collective to keep history alive, visible, and turned on, so that we may never, ever forget.

History, whether triumphant or tragic, does repeat itself. By keeping the memories alive, by reflecting on and understanding how our actions may influence tomorrow, today, humankind stands a better chance of, together, keeping former tragedies in the past, where they should stay.

Keep History Alive!