The original form of saeng-ttung-matda is thought to be saeng-dung-matda. The prefix saeng adds a sense of emphasis — "utterly unexpected," "sudden." The element dung-matda meant "to strike all at once, out of nowhere." Put together, the word came to describe a situation where something completely unforeseen happens without warning. Over time the pronunciation of saeng-dung-matda tensed into saeng-ttung-matda. The prefix saeng- is still very much alive beyond this word: in saeng-pan (something entirely different) and saeng-tte (an unreasonable demand), it carries the same sense of "totally out of left field."