Don’t I know it!

don't I know it

I know that very well or am fully aware of it (due to my particular circumstances). A: "Wow, I guess you guys still have a lot to get done before the baby comes." B: "Yeah, don't I know it."
See also: know
Farlex Dictionary of Idioms.

Don’t I know it!

exclam. That is really true! Late? Don’t I know it. I’m yawning like hot cakes.
See also: know
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • don't I know it
  • a closed book
  • closed book, a
  • as we know it
  • I know
  • (I) can't say as I do
  • can't say as I do
  • know where it's at
  • before you know where you are
  • by any chance