You know the visual cue you based it on, you know what it is, but just can't remember what number/capital substitutions you used?
You realize that you're over-thinking this, and do other things for a while: have another cup of coffee, check in on your flist, walk away from your desk to change the scenery.
Then you sit back down to log in and are still so brain twisted that the basic muscle memory of typing this password for SIX MONTHS won't kick in.
You try more distraction. You know there are only so many options because you know the basic idea so you try to roll through all of them, but you're a person and not a program and that is slow and annoying and dammit I should know my own password!
Finally you email the admin and ask them to reset for you, feeling like an incredible idiot, but needing to get some work done.
Welcome to my morning. I suppose I should have been changing this password anyway, but dude! I seriously still cannot remember what it is and despite the fact that it's no longer the password to anything this is going to drive me nuts.