How I Approach The Game
It may help to know that long before I discovered the world's first role-playing game, I was a wargamer - one who collects and plays strategy games featuring war and history as a theme, either using maps and counters or miniature figures. Wargames (and building model airplanes, tanks and ships) were among my first interests and hobbies. Therefore when I acquired my first white box containing three little brown books, I approached the new game much as I did wargames - that is, as an exercise in tactical thinking and strategy.
Around 4-5 years after discovering White Box and jumping into the emerging hobby with both feet, I acquired a new game prominently featuring investigation of the supernatural and mythos conspiracy - Call of Cthulhu - and with it, I discovered role-playing. Call of Cthulhu (CoC) is a game where players take on the role of "investigators" attempting to discover the plots of various cults and supernatural being bent on the destruction of mankind. Role-playing an investigator is a lot different than playing an adventurer in White Box. Generally, combat is to be avoided in CoC, while combat features heavily in many old school adventure games.
The term "meta-gaming" has come into frequent parlance and into my attention fairly recently as a way to describe players who make decisions based on knowledge their characters would not likely have. This is an important term in role-playing an "investigator" as one does in a game like CoC. The player knows it is a game about the mythos, the character does not and should be played as if they are surprised to discover such secrets humans were not meant to know. Knowledge of such abominations have an in-game tendency to cause character insanity, after-all.
Meta-gaming is less desirable in role-playing than it is in wargaming. In a wargame it is expected that the player will make full use of any knowledge of the game they have acquired - doing so is part of building one's strategy as a player who is "mastering" the game. My generation of early players of the world's most popular role-playing game naturally meta-gamed everything we played, including the new adventure games.
Having this awareness about the early days of the hobby and the folks who played the games in the 1970s and early 1980s, it is easier to understand some of the older modules and play styles. They are as much about "player" skill as about role-playing a character as if they are a being involved in their own reality. One might think of the older style of play as involving "gamesmanship" - the art of playing a game well.
With many decades of play "under my belt" and having played using several systems that assume somewhat different styles of play over the years I have adopted different approaches to different games. I still play games like The Fantasy Trip as a "wargame". Obviously, I take a different approach to playing Call of Cthulhu. Being able to adjust one's approach in order to play the specific game being set before you is a skill worthy of any gamer.