I just need one paragraph no more please, What is the most (surprising, interesting, confusing, or exciting) topic you learned about in Macroeconomics this term? In one paragraph, tells us about a mac

I just need one paragraph no more please, What is the most (surprising, interesting, confusing, or exciting) topic you learned about in Macroeconomics this term? In one paragraph, tells us about a macroeconomic topic, and what about it you found (surprising, interesting, confusing, exciting, etc.). topics from book   Macroeconomics -  by Paul Krugman, Robin Wells. you can chose anytopic from the book and write about it in your opinion and in your personal opinion.