for all I, you, etc. know

for all (one) knows

Said when one is uncertain or has limited details about something. I haven't talked to Marie in weeks, so, for all I know, she's not even coming to the dinner party tonight.
See also: all, know
Farlex Dictionary of Idioms.

for all ˈI, ˈyou, etc. know

(spoken) used to emphasize that you somebody does not know something: She could be dead for all I know.
See also: all, know
Farlex Partner Idioms Dictionary
See also:
  • for all (one) knows
  • for all I know
  • for all someone knows
  • happen to
  • haul (something) from (something or some place)
  • scratch (one's) head
  • scratch one's head
  • scratch your head
  • Are you writing a book?
  • dialogue with