It only took one look around to know I'd made a mistake. It was a small bus, maybe 20 people on board, and they were all staring at me as if they were being invaded. Which I guess they were.
Average age: somewhere in the mid 60s. Lots of fleece jumpers and high-waisted zip-off pants. Uh oh.
We were heading from Buenos Aires to Tigre, a river delta an hour's drive from the capital. It's a standard day-trip destination, a nice enough place to while away a few hours with its system of rivers and quaint little isolated houses.
At least, that's the theory. I was quickly realising, however, that my journey there mightn't be as exciting as I'd hoped. And I was right.
Buenos Aires is a buzzing city, a place of bustling pavements and honking traffic. Some people like to get away from that sort of thing for a while, and El Tigre is the perfect place to do it. I'm not one of those people, but I'd been told the day trip would be interesting, so I'd signed up.
Someone was shouting from the back of the bus. "Maria!" Our guide, Maria, eventually turned around. "Maria! When do you think we will have lunch? And what is the first time we'll have for the toilet?"
Maria sighed. "There is no lunch provided, but you will have time to buy some snacks later. Next toilet stop is in one hour."
There was a general nod of comprehension, then another hand shot up. "Maria! Did you say there was no lunch?"
It was going to be a long day. What followed was five hours of bus riding, river cruising and snack shopping with my new companions. Tigre itself is nice enough, but probably not the sort of day trip I'd have chosen had I known what it was going to be like.
But these things happen when you're travelling. Sometimes, you just get it all wrong. And when you've paid your money and you're on board, you just have to grit your teeth and ride it out.
The consequences of these little stuff-ups can be slight, or they can be extremely dire, depending on how long you're stuck for.
I used to work for a tour company in Europe, and most of the passengers would have a ball as we bussed them around between the continent's many beautiful drinking establishments. Some, however, would soon realise touring life was not for them – they didn't like being kept to a schedule, didn't like being crammed in a bus with a bunch of drunk Aussies and Kiwis for weeks on end.
It was pretty rare that they'd leave the tour, though. So they were staring down the barrel of four weeks of misery. And misery it was.
Everyone's made mistakes with day trips – those bus journeys to spectacular caves or tribal villages or ancient palaces that turn out to be boring slogs through a few holes in the ground, or a couple of mud huts, or an old house. By the time you realise what you've got yourself into, it's too late.
It even happens with just getting aruond. In Laos, my friends and I decided to take a private mini-bus from Luang Prabang to Phonsavan. It was a pretty long journey, so we figured we could use the extra comfort.
Trouble was, our mini-van wasn't private all – it was packed with more people than the regular bus would have been, and we had to navigate about eight hours' worth of steep, winding mountain roads in a rattly old van.
There were green faces galore from the passengers, and not a thing we could do about it except shut up, hang on and tough it out.
That's what I did in Tigre too, although without the sickness. I sat it out with my more advanced fellow passengers, buying snacks when we were told to buy snacks, going to the toilet when we were told to go to the toilet, checking out the delta.
It wasn't really my idea of a good time, but in retrospect, it could have been worse. At least I wasn't at work.
Have you ever got things totally wrong on holiday? Booked yourself on a trip you couldn't get out of?
Hope you're enjoying the Backpacker blog – there will be a new one published every Tuesday and Wednesday on the Fairfax Media websites. To contact me with any topic suggestions or personal abuse, visit my website, follow me on Twitter, or email me on firstname.lastname@example.org.