What is the most interesting/memorable question ever asked on the O’Neill answer wall?

What is the most interesting/memorable question ever asked on the O'Neill answer wall? How did you respond?
What is the most interesting/memorable question ever asked on the O’Neill answer wall? How did you respond?

There are so many interesting & memorable questions! So cruel to make me pick only one! Here’s one of many, a recent one: “Tell me something that is true, but that almost no one would agree with.” My answer: It is upsetting but true that the smell of old books is the smell of their decomposition. Which, in the case of paper, is a bit like vanilla: bit.ly/bc-old-books. Many questions make me leap into research, but this one really forced me to stop and think.