This statement indicates that your password was insecure.

If all it takes to risk guessing your password is to know your password generation logic, then the breach of any of the dozens of websites on which you have a password-protected account, may have helped the attacker in guessing your password. What happens when a password hash leak occur is that attackers generate candidate passwords based on bruteforcing results from previous leaks (Gawker, phpbb, MySpace, etc). They read them, try to understand how users picked them, and they adjust the mangling rules in their bruteforcers.

Also you would not be the first one to think your password was relatively secure when in fact it turned out to be complete crap (this guy claimed his password was secure, and even lied about its length, when it was in fact "rascal101").