It was late afternoon in the Thar Desert as we chased the sun west to Pakistan. It was hot. God, was it hot. At every step, my camel's feet sank in the sand, and even though I had a hat that would have outdone Indiana Jones' (it was cut from the hide of one of my mount's deceased peers), it was all I could do to keep from passing out and falling from his back.
With a backpacking Dutch steel engineer, a vegan Japanese art therapist and our 14-year-old Indian guide, I drifted from that orange, mirage-making heat into a state of blissful delirium as, riding into nothingness, we took turns to sing a national song: the Japanese girl sang Sakura; our guide, a beautiful Indian folk tune.
I was the anti-boozer, drunk not with liquor but the lack of it, and plodding on dry-mouthed through the sand, I belted out Dave Dobbyn's Bliss.
Beyond roads and civilisation, in the desperate lows of exhaustion and grime, I reached the final verse just as our camels happened upon a tiny thatched hut in the valley of a sand dune. It was a beacon of ecstasy in a barren land. Inside, hooked up to a solar panel, was a 1.5m glass-door fridge and - I kid you not - it was packed with glass bottles of Mountain Dew. I downed three of those icy fizzy drinks. I one-gulp necked them like a boss.
As I remember, the vegan art therapist did so too. We knew in that moment that nothing would ever match the pleasure of that sugary nectar flooding our guts. Then I moved to America and realised how prematurely I'd written off a life of soda pop pleasure. Because in America, fizzy is fantastic. Not the real stuff, mind - that's corn syrupy and gross. But the super-fake zero-calorie stuff they market as an alternative. The stuff pumped full of aspartame. I thought Mountain Dew in the desert was a pleasure I'd never repeat, now I do the Dew without doing the calories. That means it's healthy, right?
Perhaps it's because of my sickly indulgence that it surprised me this week to see Coca-Cola, for the first time, advertising to defend its diet drinks. Aspartame, the artificial zero-calorie sweetener, apparently has such a bad consumer reputation Coke deems it necessary to advertise the "benefits" of Diet Coke's sweetening ingredient.
Soda sales are dropping in the States. Diet Coke numbers dipped last year by more than 3 per cent, Diet Pepsi by more than 6. Perhaps, like me, Americans know in their gut, there's no such thing as a free lunch. Perhaps, unlike me, they're finding it easy to kick the habit.