Why would you need it if it's that kind of game where bad endings are half of the whole fun? Especially if getting them is required (i believe you need at least one specific bad end for extra content in the end of a path a).
I also have kind of a bad memory, but thankfully to their relevance to the plot, i have remembered all passwords (actually working ones and those that just appeared in the story) since autumn and never forgot them. Maybe that's because i have wrote a guide for my future self (didn't really used it while playing though). Buut i don't want to write them down here, as it is severe spoilers and i don't want anybody unfamiliar with them to see them. Anyway, good luck with recalling/rediscovering passwords. Maybe you'll write them down, too.