Why "Mother" is a great movie

"Mother" is a hugely powerful and totally engrossing Korean movie and though I'm not sure, I'll have to check this out, I believe the writer-director must also be the force behind the equally great (maybe superior) film Oasis. Mother is in many ways a conventional crime & punishment story - young man with significant mental disabilities (retardation, at the least) is accused of murdering a young woman and is clearly unable to defend himself in any way. His way over-involved mother, an impoverished vendor of herbs and unlicensed acupuncturist, takes up the case and investigates the facts to try to prove her son's innocence. I will not reveal any spoilers here for all should see this film. At times, the investigation does fall prey to the movie convention of many unlikely clues and hints falling easily into the hands of the investigator - though it does stay on the near side of credibility - unlike the utterly ridiculous plotting of Dragon Tattoo, for example. But more than the mechanism of the plot, it's a great movie because of its exploration of characters and relationships, especially that of the boy and his mother, and because of the mother's gradual and surprising awakening as the movie progresses. Great movies (and novels) are about crisis, collision of forces, leading to growth, change, knowledge - and this is the epitome. Could it be remade as an American movie, and (sad to say) find the audience it deserves? Possibly, though a big part of its beauty is its exploration of a Korean culture, poor, gritty, uneducated, that we in America never anticipate and don't often see.