Don't even remember I was there.
Since memory is something in the present, "don't" seems correct.
It sounds strange.
Saying, Didn't even remember I was there would indicate I currently do remember, which is not the case.
(I know this is addressed to Katie, but if any of you other 'wanna bees' have an opinion, I will read them, but probably only believe Katie. Of course, you could wait until she responds, then agree, but that won't earn you any points.)