Forgetting things all the time can be amnesia, or it can be a sign of pre-Alzheimer’s disease. Amnesia can occur in young people as well as in middle-aged and older people. Alzheimer’s disease usually occurs in older people over 60 years old, and amnesia in young people is mostly caused by prolonged mental stress, excessive stress, or long irregular life, excessive late nights and lack of sleep. Patients may experience near memory or distant memory impairment. Patients with pre-Alzheimer’s disease who have amnesia mainly have near-memory impairment, often showing that they cannot remember what has just happened or what they have just said, often forgetting phone numbers, forgetting to turn off the gas, often not being able to find things, etc.