Ah, okay.
I know that collecting everything in one go means you get an S-Rank. I just figured that, as I said, you could collect a token or spatula from, let's say, Glove World, and then a token/spatula from Spongebob's Pineapple, and when you went back to either level, the token or spatula was still registered as collected, added to your collection of either item, meaning that you could collect all the items in the game without trouble, and unlock extras, I presume, but to S-Rank, you have to do everything in one go.