When someone wrecks a deal that was all but done, Koreans say they "broke the santong." And the santong was a real, physical canister! Old fortune-tellers would shake a tube packed with divining sticks — the santong (算筒) — then turn it over, and read the fortune from whichever sticks slid out. So what happens if you smash that canister? The sticks scatter and no fortune can be told. From there it came to mean ruining something at the decisive moment, just as it was going smoothly. Going by the Chinese characters alone, you'd never guess it had to do with fortune-telling! Another theory traces it to santong-gye (算筒契), a lottery-style savings club in which members' names were drawn from such a canister to decide who took the pot — and "breaking the canister" wrecked the draw. Either way, the core image is the same: shattering the canister that decides the outcome. A tool once used to read destiny came down to us as an everyday word for spoiling things.