I'm too young to have cabbed anything. The closest I got was getting a packed ScotRail 158 a few years back at Christmas time. I was carrying two suitcases, and ended up in the vestibule area. A mother appeared with a double buggy, so I ended up getting hustled further and further towards the front of the train, followed by other passengers, as the train got progressively busier. The guards compartment, on the right, was open and I ended up shoved into there. From in there I could basically pretend to be driving the train.
The worst part happened when I tried to film the track (I had an long-running joke with a few friends about landing a train driving job through a highly dubious and entirely fictional sideways promotion at work). I dropped my phone into the perfect phone-width gap at the rear of the dashboard (?) desk area in front of the window. My phone had disappeared somewhere into the rear of the light cluster. I alerted the guard, who was majorly unimpressed with the whole debacle. I then spent a couple of days watching my phone traverse the railways of central Scotland via 'Find my iPhone' on my laptop, and eventually it was fished out at Haymarket depot, where I was reunited with it.