Sometimes it’s simple moments which can be all the more poignant.

I walk up the road this morning with the sun behind me, watching the long shadow of my body on the pavement in front of me. Above, the sky is clear and blue and it’s a wonderful warm morning.

I step into my office and notice how the sunlight makes every smudge and smut of dirt stand out on the window. It’s not the dirt that catches my eye but the light diffracted and yellow through the glass.

In a moment I’m taken back five years. Walking out of the meeting room across the office that same light caught my eye through the floor to ceiling windows overlooking the courtyard garden. I hear the door close behind me and I’m called across to the network team’s desk.

“You’d better sit down and watch this”, someone says as CNN appears through a forest of network monitoring, firewall and router windows.

Like many people on that day I didn’t believe what I was seeing but I still watched as my landline and mobile phone rang unaswered for 10 minutes.

Today, with a browser window playing streamed video from BBC News across the web I watch a close shot of a little girl as she walks to a pool holding a rose. A large hand from behind her guides her as she reaches over the lip of the pool and gently places the rose in the water. As the camera pulls back her mother stands behind her watching, her face both proud and full of grief as she witnesses this simple act.

The camera continues to pull back and slowly the ugly scar in Manhattan is revealed. Filled with people, the names of those who used to fill this space are being read aloud.

I sit and watch and my mind drifts back to Vesey Street and the clear bright days of Autumn. It’s a simple memory; how between the dark shadows of the skyscrapers, my shadow used to stretch out on the New York sidewalk.