I knew a woman who could work that fast in crochet. She was so smooth.
I learned knitting from my Japanese roommate a long time ago but I think she taught me English and it didn't stick. So I re-taught myself after doing right-handed crochet for awhile and learned continental - you feed yarn from the left hand for both crochet and continental. When trying English, my right hand was particularly uncooperative about tensioning yarn.
I've since picked up English to do stranded knitting along with continental and so far its the only way I can do it. My English stitches are tighter than my continental.