We sometimes forget how lucky we are to be living in the first decades of the 21st century rather than two or three centuries back or even a century ago. Our expectation of life has in many cases more than doubled over the last 150 years.

Surgery before anti-sepsis and anesthetics led to almost unbearable pain and frequent death. Cholera, typhus, typhoid, plagues killed whole communities. Tuberculosis (or consumption as it was popularly called) took away many men and women of promise. Influenza after the First World War added millions to the casualties of that horrendous conflict.

Until quite recently a diagnosis of cancer was a death sentence. Now, while many cancers are still difficult to treat and no panacea has been found, overall survival rates are continuing to improve.