I took a random stroll around a local aeronautical museum a couple of weeks ago.

How many people have actually looked at an aeroplane engine? This museum had plenty of cutaways of everything from soon-after-Wright tens of bhp engines to rocket motors. And they're all amazing. I have no idea what's involved in putting together even one of the early models, but there is such a huge amount of information and expertise in the layout, gearing, cooling, materials science, and fueling that it's almost a life's study in itself.

The museum also had an old Polaris missile. (Without warhead.) Bizarrely inside the body of the missile there were safety notices. Less bizarrely, but still straight out of Planet Surreal, there were also maintainenance annotations similar to the ones you see on university or test lab equipment. (This missile has been PAT tested and is guaranteed not to electrocute or injure anyone by accident...)