Today, I was required to give two characters from a password which hasn't been used since the last century, around 1996, I would think - and it's not even my password. I could tell from the tone of voice of the first questioner that I was close, with probably one of the two characters right, but that was not good enough for him. After some thought, I tried again, with a different interrogator, who was also 'almost prepared to admit' that I had again got one of the characters right, but not the other - it being two different character placements from the first attempt. Surprisingly, she was able to access the full password and was then able to agree that my belief of what it was was very nearly correct and we (hopefully) have addressed the issue that was the cause of the interaction being required.
I think the second interrogator was fairly impressed that I could make at least a reasonable stab at someone else's password, when it was also probably older than she was...