So I would say "Ich errinere mich nicht ....", if I could only remember german conjugation ...
Sometime late in the third year of German class, I found the answer hidden deep in the non-required parts of the grammar book -- dunno about the States, but in Norway, if it's not required it's not touched.
Apparently it was "ich erinnere mich nicht daran".
We had this scary old teacher, who would consistently ask really hard questions from the homework. Everytime someone tried to say he/she didn't remember, the teacher said "Nein, das ist falsch" (that is wrong).
When I finally managed to cough up "ich erinnere mich nicht daran" our teacher took a moment to comment, and then he said "das ist eine gute antwort" (that is a good answer). <img src="/images/graemlins/smile.gif" alt="" />
Used that one repeatedly....