So let us logically think about what you are asking. Ypu want your files locked, except for when you cant rememeber the password. So, if it were as easy as that, then no file lock software would work, because all anyone would have to do is "claim" they forgot the password, and poof it is unlocked.
There is nothing you can do.
I dont understand why you wouldnt write it down if it was so important to lock them up. If you write it down, the chances of someone finding the password written down, and know WHAT the phrase was or even for, would be highly UNLIKELY. Just dont write down folder lock password on same paper! Duh!