A: I didn’t know you are such a good speaker.

B: Thanks for the compliment. I didn’t have time to organize my thoughts, so I just spoke off the cuff.

Note: This idiom means “casually and spontaneously, without planning or preparation.” It’s fairly common for students today to write notes on their hands or wrists. In the 1930s it was common for people to write notes on their shirt cuffs — at least an idea that many were familiar with. Some say that in the early days of cinema, directors sometimes wrote notes on their cuffs during the filming of a scene, to remind themselves of what they wanted to say to the actors. This colloquial phrase of American-English origin is often hyphenated. For example: Her remarks were off-the-cuff, but very sensible.