I knew that
Lol, probably you knew that as well as I did. Not! ?
I knew dat.
We knew you knew dat! ?
I once had a professor at university who had a wonderfully dark sense of humor. When a student would preface a question by saying “This may be a stupid question, but ...,” he would jump in and say, always in an encouraging, comforting tone of voice: “Now remember, there are no stupid questions. Only stupid people.” Gosh, I loved his classes!