Wow, amazing story; so many great lines. I had to do something while listening tot he Indians in the playoffs, and decided to come here. Super job.
May I try to help your writers' block a little? I wrote a story here that might help.
http://www.fanfiction.net/s/1785210/1/The_Way_We_Were
It's the "FUll House" finale *greatly* expanded, made realistic, a bunch of new stuff in it. It might help you think about how Cookie Monster might find some things familiar, but not know why, or how he might find certain things memorable faster. If you want, you could even have Oscar help Cookie Monster recover his memory, but first you have to find him.
Realistically, amnesia victims recover earlier memories first, as I showed; you *might* throw people for a loop by having him remember he likes cookies...but not remember the others that well yet.
Who would be most likely to come up with a really wacky idea to try and help Cookie remember, like in my story - only to have him recall just before that idea? That's another thought.
Great job; hope reading mine helps a little. Of course, now you might wind up with too many ideas to choose from