To a wuss like me, it was an industrial-strength eye-opener: boarded-up windows, needles in the grass, crack vials littering the pavement and open-air drug markets aplenty. A staggering corpse of a neighbourhood, so ravaged and despairing that each time you spot a dead rat (roughly every 10 minutes), you assume it committed suicide.

In short, an obscenity; standing in stark relief to the toothless, tourist-oriented central waterfront, where our hotel, a faceless slab, sat coolly humming its way through a minor heatwave. Two worlds, same city. Madness.

Just to make the rich/poor contrast even more apparent, I had flown there first class, for the first time in my life. Not by choice, you understand. The production paid for "premium economy" tickets and, on top of these, I was unexpectedly granted an upgrade. When I stepped on board the stewardess ushered me leftward, to the promised land.

In first class, I had a seat that reclined far enough to become a flat bed. I drank champagne and ate smoked salmon from a china plate with weighty silverware, while watching a flat-screen TV. When I got bored with that, there were a couple of framed pictures on the wall. That was the weirdest, most needless touch. They weren't interesting - just photographs of city skylines - but they weren't there to be looked at. They were there to make me feel special.

"If a terrorist shoe-bombs a hole in the fuselage right now," I thought, "and the plane corkscrews toward the ocean at 1,000mph, I'm going to fix my gaze on that gilt-framed photograph and remind myself that I'm dying in the lap of luxury."

At the time, I didn't really appreciate these myriad luxuries. But come the return flight, stripped of any upgrade, I missed them so hard I went through the five stages of grief: denial, anger, bargaining, depression and acceptance. Apart from the last one.

Just as Starbucks serves buckets of hot milk in tall, grande and venti sizes instead of "small", "medium" and "large", so airline seating distinctions, whatever they are called, actually break down into Misery, Misery Lite, and the highest achievable grade, Slightly Comfortable. I was now seated in Misery Lite, which was twice - twice - the cost of mere Misery, despite the only difference being a slight spatial increase. Every aspect of Misery Lite was a just a tad worse than first class, for no reason other than it had to be, in order to keep first class seeming first class. The seat reclined (but not too far), the blanket crackled with static, the cutlery was plastic, and the meal smelt like a stomach wound. The in-flight TV had the same movie selection, but a smaller screen. Even the headphones were cheaper. If it were possible, they would make the air thinner too.

Trouble is, the people in first class never get to see any of this, because they are separated by a curtain. For all they know, the whole notion of seating classes could be a con: there might be an open fireplace and conveyor belt sushi bar at the back of the plane. Surely this is missing the point. Whip back the curtain. Treat the first-class fat cats to a guided tour of the poky sardine conditions. Only then can they appreciate their fortune.

Mind you, since comfort is relative, the airlines could, in turn, raise the spirits of the economy section by introducing a new sub-economy class, in which society's most impoverished passengers travel for free, provided they stand atop rickety stools with a noose round their necks for the duration of the flight. Suddenly your cramped economy seat will feel like a gilded throne in comparison. For about 10 minutes. Until the veins in your leg explode.

If they must take the rich/poor divide to the skyways, they could at least be creative about it. Here is the ultimate in first-class entertainment: an interactive screen displaying a floorplan of the economy section. Tap any seat, and up pops a live shot of its luckless proletarian inhabitant. Now, using a videogame-style joypad, you control his environment. You can halt his in-flight movie 40 minutes in, turn the sound so low his ears have to squint to hear it, or play it at half normal speed, so Die Hard 4 seems to be taking place underwater.

You can slowly slide his seat forward, gradually reducing his legroom for chuckles. Blow cold air in his face. Shine lights in his eyes. Remorselessly goad him with a stick. Hidden beneath his seat is a turbulence simulator: activate this if he reaches for orange juice. Seated beside him is an animatronic baby that will scream, dribble or belch half-digested rusk down the side of his face whenever you see fit.

And if physical discomfort isn't enough, why not mess with his mind? Pipe in a faked announcement from the pilot claiming the plane has accidentally flown through a timehole and will now remain airborne for eternity. Chortle through mouthfuls of roast goose as he tries to slash his own throat with his stupid plastic dinner knife. Revel in his desperation! That's what it's there for!

Of course, the inequality of air travel is a caricature of what happens on the ground: space and resources for all, doled out disproportionately. Yet no matter what relative comforts we are gifted, we are all screwed if the wings fall off. Scary thing is, the bolts holding them in place have been loosening for some time. Here endeth the metaphor. Good night.