When should you be concerned that memory loss is serious?

Common signs. Most studies of memory indicate that memory peaks in the 18-30 year old range, and then it gradually declines after that, so changes in memory are normal. Some common signs of abnormal memory problems include repeating oneself over and over, getting lost in familiar places, difficulty with eating or hygiene, difficulty with following directions, or losing track of dates, time, people, or places.
Life style. All of us do forget normally. When it interferes with daily living then it should raise concern.