"But the zeal for impenetrable computer systems rubs up against the limits of human systems."
None of this is new of course but becomes increasingly a bigger issue. At my job I have to remember about six or seven passwords and access codes though oddly one that gives access to confidential information has a company-wide password (& of course I'm being deliberately vague so my boss wouldn't freak out if she ever read this). The idea is that employees can't lock out other people or that if they're sick or unavailable the program can still be used. Makes sense in a peculiar way but not smart sense.
My solution to passwords in general is that I only have about five or six (apart from the job ones) so that if I forget which one works at a specific site/program then I just have to cycle through them all. The drawback is that if anybody ever finds out one then they might be able to log in as me on certain other sites, though they wouldn't know which ones. To me this seems just as secure as having 30 or 40 different passwords but maybe not if there was more sharing involved.