Watching old movies is generally a bad idea. They lie to you by depicting a world that doesn’t exist anymore. Historical films are even worse.
When you see a movie, you know it’s a movie. Rationally. But there’s a chunk of your brain that doesn’t understand this. It sees what it sees and files it away as reality regardless of the higher functions that know it’s unreal. So when you watch a movie from 1975, you are seeing events that took place, even if on a sound stage, in 1975 and these events are no longer accurate to reality. If you watch a movie from 1975 set in 1900 you are seeing events staged in the past about the further past and your brain is subjected to a false reality so far removed from the real world that it’s torn apart, set to scrape against itself.
Add to this the nature of past realities and their thought processes and philosophies. We do not think the way we did in 1975. In 1975, if you were curious about something, you had to go to an encyclopedia or library or person who knew the subject and learn it, with a great amount of time between the question and the answer. Now, we get answers almost instantly. Though it’s only been a few years since we gained this ability, we have mostly adapted to it and it’s hard to live without it. Similarly, the events of old films that involve people stranded or unable to call for help are misleading now, as few of us would ever dare to venture outside without the ability to call for help at almost any place or time. Those of us unfortunate enough to have lived in times of inaccessibility are also prone, in writing screenplays, to thinking of the world in a manner not consistent with modern reality. Watching old films, and watching films set in the past, exacerbates this horribly.
Certainly there are films worth studying from the past, at least for filmmakers, but their value is inevitably diminished the further they get from their time of origin, even if they are considered “timeless,” in terms of quality and relevance, they are not timeless in terms of the image they present us with. Whatever benefit we find from reading old books and watching old movies is nowhere near justifying the pernicious damage done to our minds by removing them temporarily from the present on the subconscious level.
Avoid old movies unless it’s absolutely necessary to see them, and certainly do not watch them for fun. To do so is brain damage, plain and simple.