A person who forgets things easily is often referred to as having "memory problems" or "memory issues." In a more casual context, they might be called "forgetful" or "absent-minded." In a medical context, if their forgetfulness is severe and affects daily functioning, it could be referred to as "amnesia" or "memory impairment." However, it's essential to remember that memory difficulties can have various causes, and a proper evaluation by a healthcare professional is necessary to determine the underlying reason for the forgetfulness.