The other day, while giving a lecture, I was standing in front of a whiteboard trying to write a kanji character. I know the character in my head, but the marker in my hand simply wouldn’t move. I could read it, but I couldn’t write it —it was what is known as “kanji kenbo” (kanji amnesia, or forgetting how to write kanji characters).
I am sure everyone has experienced this at least once. It is said that the direct cause is the decline in opportunities for handwrite due to our reliance on smartphones, but if we look at it from a different perspective, there is a fundamental problem of an “imbalance between input and output.”
There is a research paper published in the U.S. scientific journal Science in 2008. To put it simply, when they compared a group that continued to “review by rereading” the words they had learned with a group that continued to “review by testing themselves with quizzes,” the memory retention rate after one week was significantly different: approximately 35% for the former and approximately 80%
for the latter.
The human brain most effectively retains memories not only through “input” such as reading text or watching videos, but also through “output”, which involves trying to recall what has been inputted. But in today’s world, our lives are overwhelmingly skewed toward input. I call learning that ends with input alone “head (only) understanding”.
These days, obtaining information through videos has become the norm, making it easy to understand content that can be difficult to grasp through text alone. Many people probably find this a time-efficient way to absorb the information. However, there is a big “pitfall” here.
The act of watching videos can sometimes create the “illusion that we have experienced it ourselves.” We end up feeling satisfied, thinking we have understood it, and miss out on the opportunity to “output” that knowledge ourselves.
We need to be especially careful when passively absorbing information. This is because there is a high risk that we will rely solely on input and be satisfied with mere “head (only) understanding”. If we are actually unable to output, meaning [the skill] has not yet been mastered/acquired/internalized, and our goal is retention, then this is actually “the least time-efficient” approach.
Output always involves a certain amount of ”mental effort/hard work” This is because the process of organizing what we have learned in our own mind and expressing it through words or actions requires a corresponding amount of energy.
In modern times, “time-efficiency” has gradually become a measure of “how easily something can be done,” and by avoiding mental effort/hard work and taking the easy way out, we may be unknowingly weakening our own abilities.
Naturally, output through our body is essential in Shinshin Toitsu Aikido training as well. The research paper I mentioned earlier focused on memory retention rates, but in my own experience as an instructor, mastering techniques through actual physical practice requires far more time spent on output than on input.
To give one example, “input” means gaining new knowledge and learning the movements, and “output” means repeating the movements learned and trying to teach them to someone else. [In my own case,] this cycle [of input-output], which I always took for granted during training on the mat, had begun to break down in my daily life, and I realized that my “kanji amnesia” was one manifestation of that breakdown.
Koichi Tohei Sensei taught that “to understand means to be able to do.” Rather than stopping at mere “head (only) understanding”, he set the standard for “understanding”, as being able to actually do it with our body.
Now more than ever, with so much information readily available, why not re-evaluate the balance between our “input” and “output”, and start taking steps toward truly “mastering” what we learn?
Editor’s Note: Soshu, Koichi Tohei Sensei always said, “You have to be able to ‘do it’, not just ‘say it’”.
Translated by Mayumi Case
Edited by David Shaner
Eastern Ki Federation
https://easternkifederation.org/
Original article in Japanese: 読めるのに、書けない (Yomeru noni, Kakenai)
September 1, 2026
