Sitting on a bus the other day, I couldn’t help but overhear two women discussing their friend, who had recently been diagnosed with Alzheimer’s disease. They expressed concern that they wouldn’t be able to talk to her anymore, that she’d no longer be able to join them for lunch or trips out. Their perception of Alzheimer’s was that it was like a particularly virulent form of cancer - that it would rob them of their friend in a matter of months.