Chris' Amnesia, known as "During Chris' Disappearance (失踪中のクリス Shissō-chū no Kurisu ) is a file in Resident Evil 6.
It can be obtained in Chapter 3 of Chris Story.
Chris Redfield suffered post-traumatic amnesia after he and his team were caught in a trap sprung by Ada Wong in the Republic of Edonia. Most of his team died, and an unconscious Chris was brought to a local hospital.
Upon waking up, Chris had no recollection of who he was or what had occurred, but his mind was wracked by an overwhelming and inexplicable guilt. Chris determined to run away, and he left the hospital before anyone could check in on him.
Until Piers Nivans and the BSAA found him, Chris lived as a moody and violent drunk, hoping that he could numb himself to the pain of what happened that fateful day.
Below is a statement made by a female bartender working at the bar Chris visited regularly during his drunken stupor in eastern Europe. She was questioned by the BSAA.
He started coming around here about five months ago.
We asked who he was, but he said he didn't even remember, so we just started calling him "the stray dog." More like a bear than a dog though, from the looks of him. He's always real depressed looking, rude, never good at paying for all the booze he drinks—pretty much the worst customer we've got here. Oh, and I heard that he makes his money by doing some kind of bodyguard work, which doesn't surprise me. Uses that money to drink and pay for his hotels.
So, what? Is he in some kind of trouble or something? Ha ha. I knew someone would be after him eventually.