Thanks for the refresher.
Over my years of studying martial arts I somehow, with many excellent instructors and subtle lessons, I found I had begun to practice bits of Fudoshin.
The "why" it works for me all came together when I read "The Power Of Now" by Eckhart Tolle.
As I live In The Now, most of the time, it seems easy to avoid the remorse of the past and the anxiety of the future.
I don't claim to be an expert but I truly can practice some level Fudoshin on many days without much conscious thought.
I credit one Martial Arts instructor with a significant lesson that contributed to my understanding of Fudoshin ... although he never called it by that name.
He was capable of kicking his opponent in the head probably with a foot speed of 60 MPH. His control was extraordinary. He could see my frustration while sparing when landing a "tap" that I failed to evade or block and said being angry was my biggest enemy not my opponent. He "preached" punches and kicks thrown by an opponent that missed by 1/4 of an inch was just as good as missing by a foot.
After many hours of practice I began to have zero emotion attached to punches and kicks that I could evade or block even by tiny margins. In addition I could generally ignore those that did little damage. That left me to focus on my attack plan without mental interruption. I now implicitly use this lesson many times each week to apply it to rude people, politics, and things that don't truly matter.
In today's society I think many people are moving away from Fudoshin rather than toward it. Sad.
Thanks for the reminder.