When the world was still largely unmapped, people used to set out on expeditions in a relatively optimistic frame of mind - bad things might happen, but that wasn't the point: you were out to make your fortune, conquer new worlds, discover the unknown, all of which sounded like fun. These days, with nothing fresh to be discovered, all the optimism has leaked away; people set out on expeditions in the expectation of misery. Possibly they think it will form their characters or something.

At any rate, all the young explorers on yesterday's Tales from the Back of Beyond (Radio 4) - a series that doesn't flinch from showing the listener what a bad time can be had abroad - seemed to be looking for trouble, and they were prepared to travel a fair way to get it. To begin with, the ostensible objective of their trip was to create a fuel dump in the middle of the Sahara to help a later, larger expedition; later, they dropped that in favour of looking for meteorite samples on behalf of the Open University. Their conversation made it pretty clear that this was camouflage, though: in reality, they were out to have a perfectly ghastly time.

Mick, the expedition leader, started things off, complaining that a good number of people had let him down, making life extremely difficult: "But that's what an expedition is all about." Fergus, the narrator, added that they had had to find a replacement vehicle at the last minute, and were short of spares. "So we're basically going on a wing and a prayer. But that's what the term 'expedition' is all about." Later, after a near- fatal crash and days of heat, sand and mechanical failure had taken their toll, Paul comforted himself with the thought that "That's what expeditions are all about: discomfort, pain, problems, heartache. Et cetera."

The biggest pain they had to face was, it seemed, the annoyingly optimistic Mick. As time wore on, the other team members spoke of him with more and more open contempt - reaching a head when, toiling over a now defunct gear-box, Mick mentioned that the man who sold him the van had said that she wasn't very good going over sand. Shortly after this, Mick seemed to lose heart. Neil Walker's programme never had any, and was all the better for it.

Every so often, horrible things happen in life...But you know that before you enter into it (caller to Paul Ross on Talk Radio yesterday morning). Discuss with reference to your own pre-natal experience.