Identity Loss.

People The Guardian has a useful piece about memory loss or more specifically identity loss and how it's not uncommon:

"For some, amnesia is specific to a situation: being in car crash or witnessing a murder. In others, it is not a solitary personal experience that drifts away in time but your identity, your self. “Who am I, what have I been doing all my life?”

"Jason Bournes in the real world are usually found by police on street corners and led, in an often dishevelled and confused state, to emergency rooms. No name and no memories. Some have travelled hundreds of miles from home as part of their psychogenic fugue (fugue is Latin for flight). It is a departure from a distant physical location, but a remote place of the mind, too."