Buses don't have to reverse. If your driver knows where he's going, there'll usually be no need to engage the reverse gear.
But right now, we're reversing. Up a tiny lane somewhere in Cognac, in western France. It could even be a one-way street that we're currently trundling back along, catching the gaze of more than a few bemused locals.
I'm sitting towards the back of the bus, but I figure I should go up front and discreetly ask our driver, Toot, what's going on.
"Where are we mate?" I whisper, perching in the stairwell next to the driver's seat.
Toot glances in his mirrors, keeps reversing, stays as laconic as ever. "Dunno mate," he says in his Australian drawl. "Dunno."
You think road trips with kids are hard? Try road trips with 30 backpackers.
Welcome to the world's worst road trip. Well, my worst road trip anyway. Most journeys on four wheels tend to turn into fantastic, life-changing adventures, but so far the only thing this one is turning into is disaster.
We're lost, of course. We've been lost two or three times today and we were lost two or three times yesterday as well. Same the day before. This story is brought to you by the era before GPS technology. You might remember this period in time as one when navigating meant the actual reading of maps and the knowledge of directions.
Unfortunately that's not Toot's specialty. He's a mate of mine and a great guy to have around but on this tour the two of us are running from London down to Pamplona for the San Fermin Festival, we require slightly more directional nouse than Toot is displaying.
Fortunately, everyone else on board is drunk. They're all backpackers, most in their 20s, most Australian and living in London. The task for Toot and me is to spend five days getting them safely down to the Pamps and then hopefully safely home again.
You think road trips with kids are hard? Try road trips with 30 backpackers. They've been whinging and complaining, occasionally fighting, and generally making nuisances of themselves in the back seats. Like desperate parents placating their children with junk food, Toot and I have opted to quell any signs of mutiny on this trip with that age-old solution: beer.
We stocked up at the local supermarket last night and so far it's been doing the trick, keeping the passengers happy while we attempt to navigate ourselves through the western French tourist trail.
Right now we're on the hunt for the brandy distillery but neither Toot nor I have been here before and the directions balanced on Toot's lap don't seem to be offering much help.
We got slightly lost on the way out of Mont St Michel a couple of days ago. We missed the campsite last night and spent half an hour or so doing laps of country towns.
Today was going quite well until we arrived in Cognac and got ourselves into a narrow lane that's really not designed for a bus this size.
You want drama? There was an actual fight on board the bus yesterday. Two blokey passengers had squared up to each other after some sort of argument. Fortunately the people around them managed to gain control.
Our tour company will also never be allowed back to the campsite we stayed in last night, after some of the passengers broke into the pool at about 3am and littered the place with empty beer bottles and - strangely - a few pairs of board shorts.
In other words, Toot and I have enough to worry about without getting the directions wrong as well.
Eventually, however, our heroic driver gets us out of the tiny lane and back into the big city streets. I'm relieved.
"Where are we now?"
Toot shoots me a glance. "Still dunno mate."
We will eventually make it to the distillery and then out of Cognac. We hit the highway heading south towards Spain, and that's when the onboard toilet decides to break. Something about feeding 30 backpackers full of beer tends to ruin the plumbing system on a bus.
I close the toilet door and pretend it's not happening and Toot and Ben's Wonder Tour continues down to San Sebastian, where we fortunately won't be booted out of another campsite tonight.
The next day we finally make our way to Pamplona, our ultimate destination.
And then we see Pamplona. And then, again, we see Pamplona. It takes 20 minutes or so for me to realise we're going around and around in circles, with the city constantly on our left as we cruise the motorway.
Toot, I've just realised, is having trouble figuring out where the campsite is.
I wander down to the front of the bus, and take my seat in the stairwell next to the driver.
Toot just shakes his head. "Dunno mate."
Have you ever been on a trip where everything went wrong? Post your stories below.