It is a remarkable fact that a tremendous spate of tonogenetic and registrogenic activity occurred all over the South-East Asian linguistic area in t… - James Alan Matisoff

The long drought in Tibeto-Burman and Sino-Tibetan historical linguistics is over. The field is opening up now as never before. Where once it was the esoteric preserve of a few, it is now being enthusiastically taken up by a new generation of lively, inquiring, talented students. For much of this exciting new activity, we have Paul K. Benedict to thank.

In the Beginning was the Sino-Tibetan monosyllable, arrayed in its full consonantal and vocalic splendor. And the syllable was without tone and devoid of pitch. And monotony was on the face of the mora. And the Spirit of Change hovered over the segments flanking the syllabic nucleus.
And Change said, "Let the consonants guarding the vowel to the left and the right contribute some of their phonetic features to the vowel in the name of selfless intersegmental love, even if the consonants thereby be themselves diminished and lose some of their own substance. For their decay or loss will be the sacrifice through which Tone will be brought into the world, that linguists in some future time may rejoice."
And it was so. And the Language saw that it was good, and gradually began to exploit tonal differences for distinguishing utterances – yea, even bending them to morphological ends. And the tones were fruitful and multiplied, and diffused from tongue to tongue in the Babel of Southeast Asia.

...the more I learn about Lahu the less I think I know. It has seemed that the more fluently I came to speak the language, the more apt people were to correct my mistakes, and the less likely they were to accept unidiomatic utterances from me.