What does Ed mean when he says "I'm the message"?

After the ace of hearts, Ed believes himself to be finished with the deck. However, a surprise waits for him in the form of a joker with 26 Shipping Street written on it—Ed’s own address. Dumbfounded, Ed waits for the challenge to reveal itself.

After meeting with a man in a business suit who shows up at his door and tells him to make his way to the cemetery, Ed finds Daryl and Keith waiting at his father’s grave. The two men give him no answers, but tell him to wait longer.

Days later, a man steps into his cab, takes off his cap, and reveals himself to be the failed bank robber. The man directs him to all of the addresses at which he had fulfilled a message and tells him to look into a mirror, directing him to what he had said at the trial:

“Remember what I’m telling you. Remember it every day when you look in the mirror.” He almost smiles. “A dead man.”

Six months later, the bank robber asks Ed as he looks in the mirror: “Are you looking at a dead man now?” When Ed responds that he is not, the robber says “Well, it was worth it, then. . . .”

At this point Ed is directed to enter his own home, where a man waits for him on his couch and pets the Doorman. The man reveals himself to be the sender of the cards and more:

“I killed your father, Ed. I organized the bungled bank robbery for a time when you were there. I instructed that man to brutalize his wife. I made Daryl and Keith do all those things to you, and your mate who took you to the stone. . . .” He looks down, then up. “I did it all to you. I made you a less-than-competent taxi driver and got you to do all those things you thought you couldn’t.”

He reveals a faded yellow folder that contains every idea and conversation that Ed has had over the past six months. It is understood that he is the author of the story, placing Zusak as a character within the narrative and making Ed aware that his actions and indeed his life have been controlled by someone else. Ed, disbelieving, asks the man, “Am I real?”

The answer is in the notes:

Of course you’re real—like any thought or any story. It’s real when you’re in it.

The man leaves after telling Ed to keep on living, and the next day, Audrey comes by and asks if she can stay for good. Content and happy, Ed later thinks of something the man had said:

“If a guy like you can stand up and do what you did, well, maybe everyone can. Maybe everyone can live beyond what they’re capable of.”

This leads to his realization: if he was not merely acting of his own accord in fulfilling the cards, he was not merely the messenger. He himself was the message: he is an ordinary man who had done extraordinary things, and in doing so proved that he was capable of more than he had ever imagined.