The Buddha said: 'Which do you think is more difficult: remaining undisturbed by the sound of five hundred carts passing by; or remaining undisturbed by the sound of a violent thunderstorm?' The Buddha then explained how his teaching gave people such inner calm, that nothing could disturb them. At the end Pukkusa said: 'This very moment I blow away my old faith and inhale a new faith - in Gautama Buddha'.
Parinibbana Sutta 4:33-35