Yes. Research has shown that some people forget that they were abused or traumatized. Often, when something is too traumatic, it is forgotten but not lost from memory. This is especially so when the source of the trauma is another person. Sometimes, traumatic events are remembered later. When this happens, the person has often experienced something that reminds her or him of an original traumatic event. For many people who receive mental health services, trauma remains unrecognized as an important factor in their mental illness.