My friend said, “By the way, do you want to see the dress rehearsal for Tristan und Isolde?” “Why, yes.” I had a hunch I must have seen at least one production of this particular Wagner opera somewhere during the past forty years. You know how it is, witnessing multiple versions of the same murky set that faintly resembles a Star Trek episode and grimy opera singers in tunics wandering around a minimalist decor, eager to lean on a wall for accoustical adjustments. It all becomes a bit of a blur. A few days before the five hours of “geniessen“-ing in the opera house, I arrived at a modern and sterile high school building for a Chi Gong lesson. I could barely open my…