I'm reading about Zero-Knowledge-Proofs, in particular the argument of building a Simulator in order to prove the zero-knowledge property. As expected, there's something that doesn't click yet.
Since a simulator is using a transcript to 'fool' the verifier, I understand the idea that since the Simulator knows nothing but the transcript, then the verifier can't extract any knowledge besides the statement being challenged.
Now, this doesn't prove that the verifier is not extracting knowledge from the transcript. If the transcript per-se has the knowledge, woudn't be a problem?.
Thinking it differently, if a monkey randomly type a Calculus book... yes, the monkey knows nothing about calculus, but a reading verifier would get real knowledge by reading his work.
Am I missing something?