Jason Bourne has contracted the worst case of amnesia in movie history and it's going to last for at least four long films (three of them already released). Bourne's type of amnesia is very convenient for plotting because he doesn't know who he is but yet retains an astonishing range of martial and intellectual skills. He's a born-again innocent (a murderer with a newly minted heart of gold) who is shocked to discover that before he lost the marbles of memory, he was a professional murderer. He's rather charming in an idiot-savant-assassin way, but I suspect that his particular varieity of amnesia is not very well known to non-Hollywood neurologists.
It's a curious idea -- that an individual can be cleansed of his previous sins by losing his memory. And yet The Bourne Identity doesn't make much of this interesting moral question. "Who am I" is not investigated in the vocabulary of tragedy, as in Lear's "Who is it who can tell me who I am" but as in "what's my name, what's my address, what's my phone number." Pertinent questions, surely, but not profound ones.
On the other hand, King Lear never climbed down the outside of a building, handholds in the cracks between blocks of marble, nor, as far as I can remember, did he plummet his Fiat down a series of flights of stone stairs while being chased by a posse of sirening motorcyclists .