Don't watch the White Christmas Black Mirror episode.

I had a couple of hobbies (lucid dreaming and shamanic trance drumming) that enabled me to experience big disconnects between the subjective experience of time passing and objective measurable wall-clock time. Some dreams and trances subjectively appeared to be much longer than the wall-clock time recorded by clocks and human helpers.

I don't have any definite knowledge of what's going on with that, but I suspect some part of it is my brain retroactively manufacturing the memory of lots of time passing, and some part of it is my brain confabulating episodic memory about the dream or trance as I wake up and write it down.

Human memory is well known to be generally unreliable and full of confabulated details, so I think the most parsimonious explanation for differences between the time experienced in dreams and the objectively-measurable time that passes is that our brains are just making shit up.

Of course, the idea that your brain just lies to you about the past might be just as creepy as any other explanation.

Humanity experiences almost a million years per hour.

If the gym is sufficiently simple and well-coded, achieving a simulation speed of 367,920x real-time (simulating 42 years in one hour) is plausible. The question is whether these simulated scenarios genuinely reflect 42 years of real-world driving experience and truly represent the information that a single agent has at its disposal when making driving decisions.