something that i notice is often overlooked in older films, and even in current ones.
Mad scientists, to build even half of the crap that they build, have to have an amazing grasp of skills and abilities.
I mean, Frankenstein created life from a mismatched set of deceased body parts!
Rotwang built a sentient Automaton and the means to forge realistic flesh over it!
Professor Fate, in the 1890's-19-oughts, built one of the most advanced cars in the world in his own workshop-by hand!
death rays, shrink rays, rockets, doom lasers, Robots, mind-control machines: Mad Scientists have to be some of the smartest people in their respective worlds! no wonder they're so dangerous!