From Forbes — 

When Rick could not remember where he kept his trusted toolbox, and then forgot his computer passwords, Sandy—Rick’s wife of 40 years—initially wasn’t alarmed. Sandy misplaced stuff all the time and who can remember all those passwords anyway? But over time the signs became more ominous. Rick, a 69-year old retired truck driver with a GPS-like sense of direction, got lost driving home from the grocery store one day. Concerned, Sandy took Rick for a medical evaluation to figure out what was going on. Then they got the grim news: Rick had Alzheimer’s disease.