The recent passing of vibrant actor Charlton Heston from late-stage Alzheimer's disease makes us all stop and think about our own mortality. In particular, it is natural to wonder about your own memory, and what is 'normal' when it comes to memory loss as a result of aging.Occasional memory lapses, such as forgetting why you walked into a room or having difficulty recalling a person's name, become more common as we approach our 50s and 60s.