There are times when a good memory is distinctly unhelpful. An example is my vacation to Antarctica in 2008, which now seems like a lifetime ago.

One year in advance I had chartered a ship and invited family and friends to join me. A few months before we left for the trip, the worldwide investment firm Lehman Brothers filed for bankruptcy. What followed was either “The Great Recession” if you kept your job and home, or “The Second Great Depression” if you lost your job or your home. My busine...