Look on any internet chess forum and you’ll find much discussion of particular opening variations. The participants will look up similar games and use the latest engines running on fast computers but appear to neglect the most important thing. It is vital, in playing any opening, to understand the sort of middle game it will lead to.
Without this it’s impossible to stay well orientated if something unexpected happens, for example if an opponent fails to play the book moves. And there are also so many possible variations in the early stages that it’s impossible to remember everything anyway.
A player I’ve grown to admire immensely over the years is Anatoly Karpov. His positional understanding is extremely subtle, yet at the same time it is grounded in the classics. Here he is conducting a classic minority attack against the strong Argentinian GM, Daniel Campora: