This is a great system to create and remember great passwords.
You don’t need to remember 100 passwords if you have 1 rule set for generating them. One way to generate unique passwords is to choose a base password and then apply a rule that mashes in some form of the service name with it. For example, you may use your base password with the first two consonants and the first two vowels of the service name. Say your base password is “asdf.” (See how easy those keys are to type?). Then your password for Yahoo would be ASDFYHAO, and your password for eBay would be ASDFBYEA.