Maybe the Bank of Japan should be called the Bank of Peter Pan.

Monetary policy is notoriously tricky stuff, but for central bankers looking to validate their influential decisions it's as simple as remembering the boy who never grew up, says BoJ chief Haruhiko Kuroda.

"I trust that many of you are familiar with the story of Peter Pan, in which it says, 'the moment you doubt whether you can fly, you cease forever to be able to do it'," he said in speech about monetary policy in Tokyo on Thursday.

"Yes, what we need is a positive attitude and conviction. Indeed, each time central banks have been confronted with a wide range of problems, they have overcome the problems by conceiving new solutions."

Kuroda, a perennial optimist, unleashed a massive stimulus plan more than two years ago to stoke inflation and growth in Japan's lumbering economy.

While his efforts to force up prices have met with limited success so far, Kuroda still insists that Tokyo's war on deflation will be won.