You should revise your strategy and avoid using computers that you cannot validate it's security.
Well . . . they're not exactly public. They can only be used by law students at my school.
The fact that you have dozens of passwords has nothing to do with changed rules. At worst you should have 3 and they could be virtually identical. For instance:
shmokes
shm0kes
Shm0kes#
The scenario you describe only works in hindsight. For example. Lets say my first password is smoke. Then people start requiring 6-digit passwords. Now I have smoke and shmokes (I'm forward-thinking so I put in an extra letter). Then they're required to be 8-digit, so I change it to shmookes. Then they require there be a number in it. Not immediately thinking of the number/vowel swap idea, I go with shmookes1. Now, of course, had I known that numbers would be required later-on, I could have just chose shmokes1 way back when they required 8 characters, instead of changing it to shmookes, but I can't foresee the future. So, now lets say I
do try to predict the future. Let's say that since people
recommend using non-alphanumeric characters, I anticipate that eventually that will be a requirement, so I decide to start using shmookes-1, instead of shmookes1. Pretty clever, eh? Except that now I'm signing up for a site that requires you to choose from only eight characters, not including the hyphen. So, I can just replace the hyphen with a tilde, but what about all the sites I've already used the hyphen.
So, now lets say that my IRL name is Patrick L. And I go by the handle patrickl on various web forums. Maybe . . . just maybe, I also use that username on other things. Let's say, my bank account, or my PayPal account, or my Amazon.com account (which has my credit card stored on file). Since I know that I'm using the same username for websites with VERY sensitive data, and I know that there's a reasonably good chance that some of the owners of the web forums I belong to have plaintext access to my password, that means I need to have a
completely unrelated password for secure websites (and really, I should try to keep each of them different to minimize losses in case one of them is compromised). But now, at the very least, I'm using the "smoke" derivatives for relatively unimportant sites like web forums, but I need to start a new set of passwords for my bank accounts and other secure sites. So lets say I decide to start with a secure password right off the bat for those. Lets say I choose 0bama!sgr3at. But then I come across a website that insists on capital letters. Goddamnit. I didn't think of that one. Now I need to add capital letters to my shmookes-1 and my 0bama!sgr3at (that's a zero) passwords. What, my password needs a space in it? ---fudgesicle---! That's two more passwords to remember. Oh, this secure site (0bama) makes me choose from a list of characters that includes the hyphen, while that web forum makes me choose from a list of characters that doesn't? Great, now I need to go back to my old version of shmokes, before I put a hyphen in it. Except I actually have to create a new version, with another character in it. That's okay, I'll just go around to all my forums and change the hyphen to an exclamation point on all my web forum accounts. What? Some web forums don't allow characters at all? Some will allow hyphens, but not exclamation points?
I'm afraid your "worst" case scenario, Patrick, is FAR closer to a best case scenario.