My wife, my retired parents, and my cousins all flew in for the Paris Marathon on Sunday 12 April. They made signs. They positioned themselves at three different points along the course. Every time I rounded a corner and saw their faces, I felt the kind of stamina you cannot train for.

What surprised me afterwards was how rare that moment actually was. Gatherings like this one, with my parents healthy enough to fly and my wife and cousins free enough to show up, do not happen often, and they will happen less the older we all get. I have spent most of my career underestimating that.

I had not raced in over a decade. Running a full marathon at 38, with a knee that complains in the cold, was not on my list until my OnePointFive co-founder Matthias asked if I would do Paris with him for Free Arts NYC, a charity giving underserved children access to art and mentorship. I said yes.

The cause was personal. As a first generation Asian Australian kid who struggled to put feelings into words, piano was my sanctuary growing up. Free Arts NYC offers that same kind of access to children whose families cannot afford it. I could run for a cause like this.

Training was twelve weeks and 250 kilometres of challenges. A blizzard. -17C one Saturday when nothing in me wanted to step outside. A toenail lost. A knee that needed some physio. Long runs squeezed around work trips and being at the helm of a climate startup that does not pause for marathon prep.

For six years I have been building OnePointFive in New York, and that kind of work has a way of convincing you the rest of life can wait. Paris reminded me it cannot.

On race day, the final 10 kilometres were exactly what every other runner had warned me about. A cold still rattling in my chest. Legs that had not gone beyond a half marathon in training. Kilometres still to come.

What got me through was a picture in my head: the kids at a Free Arts NYC table, leaning over paper, expressing themselves through the colours and shapes of art. That, and the knowledge that my loved ones I had seen at every corner were still up ahead, somewhere, waiting to cheer me in.

I crossed the line in 3 hours 38 minutes. I fundraised $1,692, enough to provide around 67 kids art kits. But what I will keep is not the time, or the total. It is looking up after the line, finding my loved ones in the crowd, and knowing the thing I had run for, and the thing I had really run for, were not exactly the same.