[kijin]

There might also be a difference between a) You will be in pain for an hour, remembering the whole thing, and at the end of that hour, your memory will be wiped; and b) You will be in pain for an hour, but you will not form any memory of any part of that hour in the first place. It's the difference between saving data to a huge file and then deleting it, versus piping the data to /dev/null as it comes in. AFAIK amnestic drugs are intended to be closer to the second method.