I don't know, I'm not a wizard.

A popular phrase used in response to a reasonable question.

"How do you use this whistle?"

"I don't know, I'm not a wizard."

Don't pish on the whistle

Phrase commonly used when someone is needlessly angry at an inanimate object, potentially making a situation worse.

"This stupid remote won't work!"

"Jeez, don't pish on the whistle."
(Don't break the remote you'll just make the situation worse.)