I often change the meaning of 'relaxation', which is the most important thing to be aware of in golf, to 'become a mollusk' or 'dislocate the bones' for our students.
I keep emphasizing that the most important thing in golf is to relax, but I often see students who are practicing incorrectly and putting in more force the next day. I know that students make the same mistakes I did when I was learning golf.
However, I am guiding my students to realize what I have personally learned over a long period of time so that they can become professionals at a younger age.

--- From the "Prologue"

No matter how hard you practice every movement in golf, it's useless if the timing of the release at the end isn't right.
So release timing is so important that it takes a lifetime of practice.
However, amateur golfers tend to only study rather than practice.
That is, they lack practice and are only interested in how to hit the ball well.
Doing it that way will never improve your skills.
You have to practice countless times on the release timing in your swing.
This way, you will be able to understand the direction and quality of your ball flight, and your skills will improve through practice to reduce the deviation.

--- p.138

If you're still hitting in the 90s after five or even ten years, what's the reason? The biggest reason is a failure to understand that one turning point.
You have to give yourself time to change.
I need to breathe the new air of a new world, but I give up too soon.
I try to use a down blow, but because of my long-standing habit, I keep hitting the back of the ball instead of the front, so the ball doesn't even fly on the field.
Then, since you have to send the ball forward, you end up using an upward shot.
But we have to go through these hardships at least once.
If you hit the ground behind, try hitting the ground further ahead next time.
If that doesn't work, try hitting the ground further ahead of the ball.
But do you have the ability to hit like that? Even if you try to hit the front ground, you'll end up hitting the back ground anyway.

Okay, let's put aside the immediate match or round and try something new.
Now we need to practice so that we can play well over time.
When you strike the ground with the club, the ball will rise.
Conversely, if you lift it up, the ball just floats.
The point is, don't hit shots like this.
Let's take a look first.
Let's hit that really hard too.
Then the ball's trajectory will fly very low.
A person who knows how to hit deep with a down blow will also know how to hit thin.
That is, the depth can be adjusted.

Golfers who lift the ball are fine when they have a good lie, but have a hard time hitting it well when they have a bad lie.
For example, if the ball floats well above the grass in the rough, you can at least lift it. But if the grass is short or bare, will you be able to hit it properly? Can you always hit the ball from a good lie on the course? Absolutely not.

--- p.157