Learning from Simplicity: the True "One-Fly" Rig

Daniel Galhardo posts in interesting proposal on his Tenkara blog: that using one fly, in one size, for all fish regardless of hatch activity, will inevitably improve technique.
“Ever since getting into the discipline of using one fly pattern/style only, with no great concern for choosing the ]right] fly, but rather focusing proper fishing technique (presentation and manipulation of the fly), there have been moments of doubt.”