as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
generate sentences that use the idiom once in a blue moon.
user
he only comes home once in a blue moon.
she comes out of her shell once in a blue moon. 
the train only passes by here once in a blue moon. 
we get a chance to do this activity once in a blue moon.
assistant