I was WAY older than I should have been when I learned that an “engineer” didn’t exclusively mean someone who drove trains for a living. Curiously, in the field of trains there’s a second synonym profession title: a conductor. There’s also dual meaning between train like a locomotive and train like to teach.
There’s gotta be some clever joke where an engineer and a conductor walk into a train car… but I’ve only had one cup of coffee today and can’t come up with anything clever enough.