Sometimes, it takes more than half a life to gather a basic understanding, maybe even of the very core of one’s own profession. It is a sobering experience to suddenly realise: oh dear, I have always been doing it completely the wrong way.
It is unsettling, it questions all your doing, maybe your whole life so far.

Presenting during a workshop I was invited to organise at the ICCS 2011 Conference, Singapore.
I feel very grateful for the three decades I was allowed to spend in scientific research and teaching, where questioning your own understanding (and that of your students) is the daily bread and butter. While some people quickly and self-confidently shout “I know, I know!”, the trained scientist might carefully respond “I might have a more or less educated guess on that matter …”.
Not knowing is the precondition for asking, for inquiring and investigating further … and maybe for understanding a bit better, for the time being. “I know” is the end of learning. It prevents you from even realising you have not yet understood anything (this level of ignorance is called the Dunning-Kurger effect).
Before I came here I was confused about this subject. Having listened to your lecture I am still confused. But on a higher level.
(possibly wrongly) attributed to the great physicist Enrico Fermi
I think I can safely say that nobody understands quantum mechanics.
Richard Feynman, an equally great physicist about the core of his work

Supervising (much brighter than me) PhD students at Tohoku University, Sendai, 2014.
Alas, the science I love and studied for so long kept me misunderstand one very basic fact: being used to interact with exceptionally bright and educated scholars (most of them much brighter and better educated than me), I always assumed processing enormous amounts of information and producing enormous amounts of text is just normal. It is the way we are, not just us scientists, but us human beings in this world. The very meaning of homo sapiens.

With senior scientists having fun discussing science (and else) at a conference dinner, Tokyo, 2007.
Listening to condensed high level scientific presentations hour after hour for days during a conference was pure joy, a pleasure to be continued in conversations over coffee breaks and dinner. Delivering ninety minutes of fluent free speech on a research topic on a weekly or even daily schedule was part of the usual teaching obligation, and the ability to do so a necessary requirement for any even slightly advanced position in academia.

With young scientists having fun discussing science (and nothing else, unfortunately) after a conference in Hong Kong, 2005.
It just occurred to me, thanks to some harsh feed-back from my young assistant, that a majority of people usually are not like my former peers from the ivory tower. Their way of learning and understanding does not work well along words and thoughts. As soon as I start talking, very quickly, it is all too much.
I always assumed the Buddhist term upāya-kauśalya (Sanskrit: उपायकौशल्य, Japanese 方便(ほうべん)), usually translated as “skillful means”, referred to finding the right words for your audience when teaching Buddhism. High level condensed talk for the educated and experienced, basic words and fundamental concepts detailed out for the beginners and the intellectually challenged or untrained mind.

Announcement of my talk at the Department of Aeronautical Engineering, Kyoto University, 2011.
While I still want to believe there is a very small fraction of people who enjoy to embark on a journey which requires long reading or listening, deep thinking and questioning all they knew, I came to the conclusion that talking more than a few words during a Sesshin or at the Dojo usually makes no sense. Besides providing very basic information, for example how to breath while doing Zazen, or how not to damage your neighbour while exercising with a sword or brush, and maybe some kindergarten 101 such as not to enter the Zendo with shoes and what it means when a door is open or closed, I should better be silent. Otherwise my words are misunderstood, or not understood at all.
Too much talking gets on your nerves, you feel like back in school, or even worse, like at home with your parents, lecturing you. After a few years with your teacher you feel bored, hearing the same words over and over again, shutting your ears from the inside while having hardly understood anything of what he has been talking about all the time.
I love listening to your talks. I usually don’t understand a word, but your voice calms me down.
a former Zen student
It is going on my nerves, listening to you is like listening to my mum. I always already know what comes next and have to shut my ears from inside not to get mad.
a young Zen student
… when they speak great swelling words of emptiness …
The Bible, 2 Peter 2:18

With my former teacher who is teaching by demonstrating, Benediktushof 2011.
I remember very well having had similar emotions towards my former Zen and Hitsuzendo teacher, with whom I closely worked for 13 years. His teachings were very basic, never sophisticated or intellectually demanding, usually down to the core of our practice – and highly repetitive.
Soon I began to develop a strong aversion to his constant advise. “Left hand on the paper!”, “Hold the brush straight!” I hear is words, maybe for the hundredth time while writing, and got angry I have to listen to such fundamentals for the other beginners in my second or third year of training with him. When I suddenly I realised I always have been swaying my brush around, never ever keeping it straight, with the left hand comfortably resting on my knee while writing. He had always been talking to me, the same basic thing, year after year. It struck me like a bang on my head, and I felt much ashamed, and grateful for his enormous patience.
I do not need to explain Zen. I demonstrate Zen with my whole body, 24 hours a day
my former teacher

My former teacher during a visit in Aachen, probably demonstrating something to me I did not get.
So my recent realisation, questioning all I did in teaching Zen and Hitsuzendo so far, is related to upaya or skillful means. My above mentioned academic background greatly mislead me. Upaya is rarely about finding the right words (in spite of Zen being amongst the most prolific Buddhist branches when it comes to writing and lecturing). It is about the right teaching beyond words. The words are almost useless.
Even my most basic oral advise in Hitsuzendo
Closely look at your writing afterwards, always, every time !
is being gracefully ignored. Why should I say anything more ?

Bodhidharma by Hakuin Ekaku(白隠 慧鶴 1686-1769), from our Dojo’s collection.
Not that I didn’t know it. Not that I didn’t put the utmost emphasis on all my conduct beyond just producing words. But all that was sadly covered and disguised by my lecture mode on autopilot. The famous words attributed to Bodhidharma were proudly on display at our Dojo on a calligraphy by Hakuin:
教外別傳 A special transmission outside the scriptures
不立文字 Not founded upon words and letters
直指人心 Pointing directly at the human mind
見性成佛 Seeing into one’s nature and attaining Buddhahood
I read it every day, yet I thought that pointing directly at the human mind was about finding the right words.
And while we are at it: another severe drawback of my training within an international scientific community related to words may be my careful and mostly polite way of speaking (1), and my bias towards answering any question.
While thinking or talking, I always carefully assume the other person might have a point, might be right, no matter how rude or uninformed their approach may appear to me. “Let me think about it!” is my usual reply when I believe I just had been told or asked some nonsense, instead of a loud and clear “No, you are wrong!”. Or a bang on the head, which, speaking of upaya, might be the appropriate reply to most things I encounter within the Zen context.
So may it be, my “Great Swelling Words” will hopefully sweep away in silence. I promise to try my very best restricting myself to writing (which anyone who is not interested can safely ignore) and rare and short Zen talks during Sesshin, and such give way to “steal my Zen” (2) by carefully watching. Concerning a solid bang on the head of my students, I am not yet sure if this is really my way, we will see. Maybe I come up with something else …
Yes, and how many times can a man turn his head
And pretend that he just doesn’t see?
The answer, my friend, is blowin’ in the wind
The answer is blowin’ in the wind
Yes, and how many times must a man look up
Before he can see the sky?
David Bowie
–
(1) Not all scientists I witnessed were always polite and careful speakers, I experienced some loud shouting and aggression on the verge of fight in front of the audience as well, but that was a shameful exception. Excellence in science does not always correlate with social intelligence.
(2) Referring to the traditional Japanese concept of an apprentice “stealing” a technique from the master, called 技を盗む (わざをぬすむ ), meaning learning through intense observation and imitation rather than direct instruction.