The future queen volunteered in the Auxiliary Transport Service in WW2

Excerpt from the Evening-Standard, May 2020:

Newspapers at the time dubbed her “Princess Auto Mechanic” and reported that the King had ordered that she ‘is to be treated exactly the same as any other student officer, with no special privileges because of personal rank.’

Pictures and videos show her dressed in a boiler suit working on a car engine, pulling out spark plugs and in her smart ATS uniform as she drove a truck.

Princess Elizabeth learned to tear apart, repair and build engines and additionally learned to drive a number of different military vehicles, including trucks and ambulances.
https://www.standard.co.uk/insider/royals/queen-elizabeth-world-war-two-mechanic-ve-day-a4432841.html

I think this is one of the coolest things about the late Queen.