One of the most difficult conversations you can have in life is with a parent or peer who is becoming too old and infirm to work. Whether the infirmity is physical or mental, often your loved one is the last person to realise his own deficiencies, so he may interpret respectful, genuine concern as a personal attack.

This conversation is difficult enough when it’s conducted entirely in private with friends and family. It’s infinitely more difficult when it plays out in public and involves the president of the United States.