I think this is where Park Chan-Wook succeeded at what he initially set out to do with Mr. Vengeance, Oldboy's predecessor and first part of his (though admittedly quite arbitrary) "revenge"-trilogy - to leave you feeling shaken and mentally somehow bruised. However, with Oldboy I had the genuine suspicion that I'd just witnessed film history in the making; a suspicion which, needless to say, hasn't abated. In any case, Park's idol Hitchcock famously said that you should be able to watch a film without sound and/or dialogue and still find yourself able to follow the story and, having first seen Oldboy in Korean without subtitles, I can vouch that it passes this particular test.