Building blocks of a great impression

I remember an experience I had many years ago as a high school student in Germany. Our geography teacher used to play an "association game" with us to make lessons more interesting.

"What comes to your mind when I say Egypt?" he would ask. The answer he expected was "Nile". For Brazil, he expected the Amazon river and so on.

One day, he wanted a prompt for "China". Spontaneously, I said "Great Wall". The teacher was irritated and reminded me that this was a geography class. He wanted to hear "Yangtze River" or maybe "Gobi Desert", so he asked me to explain my answer.