I can remember it perfectly- every single detail of every single second of that evening somewhere in the suburbs of Paris.

Mentally preparing myself for the fact that I was about to see people shot dead.

Looking down the wrong end of a gun, telling myself I might be about to die.

Being very calm and collected as I walked towards the gunman taking control of the situation and talking to him.

Feeling the pointed end of a knife in my neck.

Watching the gang flee, waiting till they were way out of sight before I dared allow myself to lose control and collapse in a gibbering wreck.

So, 20 years later I can remember every single second of what happened.

My question is:

So why was it that faced with a photo identity parade I identified the wrong people? When the police told me I'd got it wrong I was immediately able to identify the correct people. The police told me they believed me but couldn't use what I said as evidence as I'd got it wrong first time.

The friendly gendarme just shrugged his shoulders and said "It happens all the time. People rarely identify the right people, it must be some kind of mental block" before giving me a coffee and reassuring me that they were in custody.

Isn't it odd how you remember some things so vividly, yet draw a mental blank over the precise details that really matter?