Periodically Zen Buddhists gather for sesshin, or 5-10 day silent meditation retreats. During sesshin participants follow a rigorous schedule from dawn until dusk that includes 5-10 hours a day of seated meditation (and sometimes more).
Sesshin is a powerful tool for spiritual transformation.
A little like a meditation marathon, sesshin requires enormous endurance. Experiences during sesshin include periods of bliss, boredom, profound stillness and peace, agitation, exquisite appreciation for just-this-moment, tremendous aversion to just-this-moment, deeper concentration than is usually possible outside of sesshin, and periods of having to endure compulsive thought patterns that repeat endlessly like broken records. Experiences include profound insights of either a universal or personal nature, and seemingly prolonged periods of frustration, fruitless striving, sleepiness and dullness. There can be periods of great physical or emotional discomfort or pain, and periods when we settle so completely that this pain is transcended.
And usually you will experience at least a little of every of one of these things over the course of a single sesshin.
The irony is that when you tell people you are going to a meditation retreat they often sigh enviously because they think you are going away for a week of pleasant peacefulness. Ha! You think, “If they only knew how I was going to spend my vacation time, they would think I was crazy.” And, sometime during the sesshin, when you enter your fourth or fifth straight hour of painful, dull meditation, you will probably think you are crazy, too.
What keeps people coming back to sesshin, despite the sometimes grueling nature of it? It’s not the moments of a sesshin that are peaceful and pleasant, although those are very nice. It’s the overall effect on our Zen practice and our life.
Spending a week in sesshin is comparable to spending time in graduate school, or in an intensive training course, the subject matter being your own mind. You may learn a great deal studying in your spare time, but nothing compares to setting aside the time and energy to delve as deeply into a subject as you possibly can.
What we study in sesshin is not about the content of our mind, although we will end up learning a great deal about that. What we are focusing on is how we use our mind. Or, actually, our “body-mind,” because there is no separation between our body and our mind. We ended up with this human body-mind, and it is often assumed that by the time we have turned 18 – or, perhaps, 21, or 30, but certainly by 40 or 50 – we know how to be that body-mind and fulfill its full potential. Nothing could be further from the truth.
There are infinite ways to screw up this human life, or at least to compromise it. We unknowingly dwell in delusion and misunderstanding, and create suffering for ourselves and others – deliberately or with the best of intentions. We let skeletons hide in our closets until they bust out at some moment we are at our most vulnerable. We let our fears control us and chase away the intimacy we crave. On the other hand, there are infinite ways to deepen, expand, clarify and intensify our experience of this human life. No subject can be studied completely, to the point that everything is known, so of course this is the case with so profound a subject as how to best use this incredible instrument called a human body-mind.
If you are suffering deeply, going to sesshin to face that suffering can seem very daunting. Indeed, your experience of sesshin may be quite challenging as you try to allow yourself to see and fully experience what is troubling you. It is generally always worth it.
If you don’t think sesshin sounds worth it because your life is good enough as it is, that’s fine. However, to quote one of our zen ancestors, “When dharma does not fill your whole body and mind, you think it is already sufficient. When dharma fills your body and mind, you understand that something is missing.” Of course something is missing; in an infinite universe, how could you have it all?
 From the “Genjo Koan” by Eihei Dogen, translated by Kaz Tanahashi.