I think I want some chocolate cake for dessert!

Cake? You never have dessert!

I like to have it once in a blue moon!

Hey babe! Do you want to watch a movie tonight?

Sure. What's on TV?

How about we go to the cinema?

We only do that once in a blue moon.

Great idea. It has been so long  since we have been to the cinema.

Hi boss. I'm sorry, but I'm feeling  sick today and I can't come to work.

Oh... I'm sorry to hear that. You're  so healthy, you never get sick.

I know! I guess everyone gets  sick once in a blue moon.

Get some rest. I hope you feel better soon!