What's that got to do with the price of eggs American rhetorical question
This rhetorical question indicates that something said beforehand goes off-topic or has no relevance to the current discussion.
A: I can't believe that Linda won the competition. B: What will you do tomorrow? A: What's that got to do with the price of eggs?
A: What should we cook for dinner? B: What's that got to do with the price of eggs? We're discussing the new project.
I agree with your opinion, but what's that got to do with the price of eggs? Our topic is "Workplace conflict".
This phrase emphasize that Christmas takes place once a year time, so you should grab this chance to indulge yourself and be good to others.
I've eaten a little more than usual as today is Christmas and Christmas comes but once a year, right?