Tech demos don't always go to plan.
Today it was my turn, as a virtual reality demo here at the CES tech show went badly wrong.
It started well. In an elegant hotel suite at the top of the famous strip, gaming chip-maker Nvidia gave a slick presentation about its Shield product - an Android-based TV connected device that offers a host of high quality entertainment options, including VR.
Then, it was time to try some new VR titles.
Overall, I've been quietly impressed with VR. I've tried various headsets in various stages of development and seen some amazing virtual sights.
At home, I'm starting to think my family members are growing Google Cardboards out of their foreheads - although I know some VR aficionados say they don't count.
The day's first experience was mind blowing. Inside a small empty room, wearing an HTC Vive, I climbed Mount Everest.
The graphics were superb - actual footage provided by the makers of the movie Everest. And wherever I looked - up down, around - there I was in the Himalayas.
Even a glitch, when my hands went through the mountain, didn't dampen the moment - that's how intense it was.
I recorded my first impressions for our radio show Tech Tent as I stumbled tentatively around the mountain, teetering over vast ice chasms on tiny bridges and climbing a vertical ladder up a sheer face known as Death Falls.
Listening back to the recording, my voice actually cracked with emotion when I reached the top.
Everest duly conquered, it was time to take a trip into outer space with a demo of another new game called Adr1ft.
The Rift VR headset applied, I was given an Xbox controller. Now, I'm familiar enough with them but not to the extent that they are like an extra hand - and of course with the headset on you can't actually see it.
Suddenly, I was floating inside a glass windowed dome above earth not dissimilar to the cupola on board the International Space Station.
Various bits of debris surrounded me. It was powerful - but the constrictions of being inside a virtual space helmet gave the visuals a tighter window than I had expected.
The developer, Adam Orth, is passionate about VR. He started to tell me that Adr1ft was based on personal experience.
"Have you been into space?" I asked, as I sat through the tuition video - although I have to admit by the time it had finished I'd already forgotten which buttons did what, and I was also distracted by trying to explain what was around me for the radio show.
"No. It was… metaphorical," he answered.
But before I could find out what he meant, suddenly, I found I just couldn't move.
Nothing responded as I expected. I couldn't even get to the space ship hatch to get outside and start my mission. I started to feel very hot and very disorientated. I was tumbling around, bumping into walls and debris and no longer knew which way was up. My virtual space helmet visor was cracking.
Within about 30 seconds I wanted to rip the helmet off and run to the bathroom.
I asked to stop.
Adam was totally thrown.
"Let me just get you out of the ship…." he said, taking the control from my hands.
But it was too much - I had to remove the headset.
He looked genuinely crushed and I felt terrible.
"We've never had this reaction before," he said.
He started pressing buttons and his face lit up.
"The controller is configured wrong!" he said.
"No wonder you couldn't do it."
I'm not sure whether this was a polite ruse to save my dignity.
"I still don't think I feel very confident about continuing," I said sadly.
There was a long pause.
"I'm sorry…" I tried.
"Would you tell me about your inspiration for the game?"
He didn't respond.
I sensed my time was up. After some small talk we said a polite goodbye and Mr Orth did ask if I wanted to continue, but I think we both knew the moment had passed. And I was seriously worried about throwing up.
I left the suite, immediately took a wrong turn and found myself totally lost in the labyrinth that is the average Las Vegas hotel.
When I finally did get outside, I walked the wrong way up the strip in the pouring rain. The disorientation stayed with me for about half an hour afterwards, and I felt too nauseous to get in a taxi.
Now - it could be that I'm just not cut out for VR gaming. It could also be that I'm nursing a winter cold and I'm not fighting fit for space travel.
But now I have experienced first-hand the weirdness that VR can induce - seemingly very suddenly - and I didn't like it. I am in a very small minority, I am told, and I hadn't felt it before.
"There's always going to be a small percentage of the population that gets motion sickness, there's no way around that," said Brian Blau from the tech research firm Gartner.
"But for most people, it usually won't be a problem.
"For the most part, when there's motion sickness it's caused by the app. Developers have to work hard to avoid types of situations that cause the problem.
"Making VR is not easy, it will take time and experience."
My experience hasn't put me off virtual reality, but it has made me cautious.
And I guess my future career as an astronaut is dead in the water.