渾然不知

浑然不知
húnránbùzhī
  1. to be totally oblivious (to sth)
  2. to have no idea about sth

CEDICT

一點也不知道。

重編國語辭典

Entry Composition

1 渾然 húnrán
  1. completely
  2. absolutely
  3. undivided
  4. totally mixed up
  5. muddled
2 不知 bùzhī
  1. not to know
  2. unaware
  3. unknowingly
  4. fig. not to admit (defeat, hardships, tiredness etc)