EMOTIONS
Of course it is not as simple as losing one's memory. A crucial aspect about brain injury, stroke and dementia is how one responds or copes with it and what sense one makes of what is going on.
In some cases people accept their limitations, with some regrets, but learn to adapt usually by constricting their lives. They stay in more, keep close to those they trust, they stick to routines and avoid mentally overloading themselves.
In other cases people react quite catastrophically to a failing memory. They are overwhelmed and cannot make sense of what is happening to them. Especially in the dementias it seems common for people to be highly confused and anxious. They may desperately deny what is happening, they may accuse other people of deliberate acts to cover up their own memory failings, they may become worried or even depressed.