殊不知

shūbùzhī
  1. little imagined
  2. scarcely realized

CEDICT

to have been scarcely imagined, expected or realised

Wiktionary

竟不知道。

重編國語辭典

Entry Composition

1 殊 shū
  1. (literary) to kill; to behead; to sever; to separate; to surpass
  2. (bound form) different
  3. (bound form) special; remarkable
  4. (literary) very; extremely
2 不知 bùzhī
  1. not to know
  2. unaware
  3. unknowingly
  4. fig. not to admit (defeat, hardships, tiredness etc)