Darn lack of perfective/imperfective distinction in English :| Makes everything more complicated, because then often "well... one version is a lot more probable, but the other one is technically correct as well". It does make learning harder... but what can one do. Added your answer.
No, that would work in Russian (maybe you know some), but not in Polish. In Polish, every grammatical person has their own form, and it also accounts for gender of the subject of the sentence.
So, a man will say "Pamiętam, że sprzedawałem ryby" and a woman will say "Pamiętam, że sprzedawałam ryby".