The moments we treasure so rarely come to us on a schedule, waiting in the wings for Christmas or a birthday to make their appearance. Instead, they jump us in our daily lives. Maybe there's one just around the corner for you, O Reader, today, this August the 30th. There certainly was for me.

It was my night out; the Hub was taking care of the baby. Usually I spend the evening in a cafe, preparing nodes on my Palm and folding keyboard. But I saw a listing for 2001: A Space Odessey in the paper, and walked over to the cinema to see it. Unfortunately, the paper had it wrong: the film doesn't start until mid-September. But the noding mood was broken, so I decided to walk.

Walking for me is the universal solvent. All my best thoughts, all my best conversations, have happened to the rhythm of putting one foot in front of another, uphill and down. And Edinburgh is a good city for walking in. There's always something else to see, from the secretive cobbled closes off of the Royal Mile to the formal Georgian elegance of the New Town. I decided to go to Holyrood Park, where the grassy slopes of Arthur's Seat and the Salisbury Crags loom over the city. Approaching the park, looking at the long cliff face of the Crags, I felt the first stirrings of a complex of emotions I could not yet identify.

The climb up the crags is strenuous, and I took it at a brisk pace. Soon my legs started to ache and the endorphins began to sing in my brain. I reached the clifftops just as the sun dipped below the horizon, and looked down at the city outspread at my feet. In front of me, across the Old Town, the Castle glowed in its floodlights. Further on, the city lights stretched to the Firth of Forth; beyond it, the grassy hills of Fife lay in shadow. Above this spectacle, the clouds glowed like molten gold. I glanced over my shoulder to see the nearly full moon turning its half of the sky to silver. The wind blew the echoes of bagpipes toward me from the Tattoo.

I glanced back down at Edinburgh, and felt the first stirrings of vertigo. I was reminded of Milan Kundera's definition in The Unbearable Lightness of Being - vertigo is the desire to fall, the call of the void. And on the back of that desire came a tidal wave of feelings: not an epiphany, but a consolidation of the last ten years, all in a moment. It's been a hard decade - turning away from the self-destructiveness of my university years (not an interesting, extroverted self-destructiveness that starts by trashing the body, but the boring introverted kind that eats one from the inside, making a desert of the heart first, so that nothing else matters), forgiving the unforgiveable so as to put it behind me, nervous breakdowns and bad decisions, miscarriage and loss, all of the painful steps and hard choices that have brought me here.

These things are a price I have paid, and what I have bought with them is joy. My blood sings in my veins, the breath burns in my chest like fire, and tears blur the lights below and above me. I don't laugh aloud - this is too serious and too wonderful for laughter.

The moment passes. The wind rustles through the grass, sounding like the pebbles on a beach as a great wave ebbs. But I am not the same as I was before the tsunami of emotion broke upon me. I am conscious, now, of having found a balance I've been searching for for years. It's the reverse of a mid-life crisis.

The air has an edge to it as night begins to fall, and I hurry off the hill while I can still see the path. I have promises to keep, and I'm looking forward to getting home.