This is a good way to put it. I don't yet understand what makes an opening such a personality. Like, what the "attitude" of an opening is beyond "white tries to dominate the center with a fiancetto from the king-side and crush the opponents defenses through pressure on f7" (this is like how every Wikipedia entry on openings is written). Great, thanks! I think this is probably one of the things that separates enthusiasts from naturals, because while I get the basic point of the sentence, I don't see how that plays out for 10 moves. Or maybe I'm overthinking it. I keep waiting for it to "click" one day.
But yes, seeing someone deviate from a memorized opening doesn't help me win either!
The way you win in chess is to create an imbalance and then exploit your half of it. The imbalance may be on many facets, like different pieces or pawn structure or activity.
Some openings create few imbalances (e.g. Exchange Slav) and these are drawish.
This is a very helpful way for me to think about future moves, because I can add to my mental checklist: "scan for any possible imbalances."
You mentioned three facets: piece imbalance, pawn structures, and weaknesses near the king (or other pieces).
Are there more?
- Minor pieces (bishops vs knights)
- Pawn structure
- Space
- Material
- Files and squares
- Development
- Initiative
I would add how much time is left on the clock, though that is not a feature of the board.
An example: say you have a bishop and your opponent has a knight. This is an imbalance, and you want to exploit it by making your bishop better than their knight. Concretely that means trading pawns, to open up the game, so your bishop can bring its long-range strengths to bear.
The issue I've encountered with memorizing openings is that it assumes both sides are playing perfect openings that complement each other. In reality, in my "lower rated" games, my opponent is likely to make suboptimal moves against the opening I memorized. There are ways to punish their moves, but I would've needed to memorized that. So, I have to come up with changes to the memorized opening on the spot.
Going through the checklist allows me to play without memorizing movesets even though the moves I make are not the "best".