Golf is way more than a handicap index, no less the score of a few rounds.
I try to play for enjoyment and the challenge of improving. It can be equally frustrating for high handicappers, just the numbers are different. When we blow up a round, the scores are more like 120.
Forget the numbers and just play the best you can on each and every shot. That's the real challenge.
And if I can give one piece of advice, and it's one of the biggest difference between >20 hc golfers & <15's, it's course management. Single-digit handicappers, generally speaking, don't have blow-up holes. I can't tell you the last time I carded greater than double-bogey on a hole...and even doubles are rare for me.
Why? Because I follow Jack Nicklaus' advice - A bad shot has to be followed up with a smart shot. We all hit bad shots. It's what you do with it next that's key.
It's kinda funny, and ironic, that when a high-handicapper finds themself in a bad spot, let's say a shot from the woods, that they try the heroic shot. But a single-sigit player in the same situation more often than not just punches it back into the fairway. The single-digit basically accepts his shot hit into the woods is likely going to add a stroke to his score, but he makes sure a higher number is taken out of possibility. I actually find myself saying that a lot when I get to a shot in the woods - 'Play for the five, Jer' (if it's a par-4 hole). Swallow your ego.
Often, after I punch back to the fairway, I may have like 125 to the green now, lying two. I can usually put it somewhere on the green from there & I got a decent shot at par, but no worse than a bogey. Meanwhile the high-handicapper is still hacking in the woods lying 5.
Lower handicappers, again generally speaking, understand their games and THE game better. It ain't how, it's how many. Get that ball in the hole in the fewest strokes possible.