It is arguably the UK’s biggest killer.  It will touch the lives of half of us, and it’s the illness that people over 65 fear the most.  It is of course dementia, a group of symptoms that damage the brain and get worse over time.  An early diagnosis is crucial - and devastating.  There is as yet no cure, but there is care, treatment and support.  We visit a dementia cafe in Norfolk and talk to people living with the condition.