It might start with the constant search for glasses or keys and perhaps forgetting the name of a recently visited restaurant, but the distinguishing factor between forgetfulness and Alzheimer’s disease is the ability to retrace your steps to find a lost object or recall the evening some time later.

For Nick Sheldon, the first signs that Jane, his partner of 44 years, had the most common form of dementia was when she would repeatedly ask the same question soon after Nick had answered.