I know. You’ve heard this so many times before it sounds like a mantra. What does it really mean, though? It means that every shot you hit adds one stroke to your score, so you need to get the greatest value for that one additional stroke that you can.
That is expressed by your hitting the best shot you possibly can from wherever you are. Not the shot you would like to hit, or not the best shot that could be hit (by someone who’s better than you), or not the shot think you have to hit, but the best shot you can hit.
Isolate each shot from its scoring value and give each shot the same amount of your attention. A six-foot birdie putt and a six-foot par putt both count one. The attention you give to them does not change because of the sequence of events that led up to them.
Once you can give your attention to shots instead of score, that’s when your scores will start to fall without you having improved your golf skills one bit.