Practice is all about uncovering our core beliefs - and this includes uncovering our core beliefs about the nature of practice itself and what we expect to gain from it. Because even though we may recite the line in the Heart Sutra ( No path, no wisdom, and no gain) countless times, it is simply in our nature, deep down, to have some hope, some picture of what we expect to gain from all this practice that we're putting so much time and effort into.
Now certainly there are some seemingly straight forward rewards of practice. Generally speaking, we may become somewhat calmer; build up our capacities for concentration or endurance; become steadier and more reliable as a result of the rigors and discipline of the zendo. But the fact is that the deeper we allow practice to penetrate into our core beliefs, the more we are bound to be disappointed by practice - because at the deepest level neither practice nor life is going to conform what we want them to be. I just came across a quote by the philosopher C.I. Lewis: "There is no a priori reason to believe that when we discover the truth it will turn out to be interesting." When we go looking for the truth, we all go armed with some picture of what we want the truth to look like, but the truth isn't interested in our pictures!
I remember when I first started going out to San Diego to attend sesshin with Joko, I planned one trip with an old Zen friend whom I had practiced with in New York for many years. In most ways he was a far better Zen student than I was - he had attended many, many sesshins over the years with many different teachers, some very strict and demanding, and was capable great discipline and physical endurance. I've never been that tough! But he really approached Zen the way somebody might take up something like mountain climbing - he exalted in the difficulty of it all and was exhilarated by the intensity of his efforts and his sense of mastering something that would have once seemed impossible. Anyway, we had planned to go to San Diego together and were in the airport waiting for our flight, which kept getting delayed later and later. And all of a sudden he got up and said, "You know, this isn't any fun!" And he walked out and went home. As far as I know that was the end of his Zen career! His core belief about practice had been bought right up to the surface - he wanted practice to be intense, difficult, exhilarating, something he could be proud to master. And all of a sudden, after all those years of sesshins, it didn't feel anything like that.
Those moments of intense disappointment are really our greatest opportunity. In those moments we are given the chance to choose life as it is over our old core beliefs about life. But the truth when we see it may not be very "interesting," and we will be tempted to hold on to our fantasies, which may be much more heroic or romantic or tragic than this ordinary moment. The paradox is that the greatest rewards of practice come only when we allow ourselves to experience the greatest disappointments.