I came up with this question because of my personal experience. I think it may help you understand my question better, so I will describe it briefly.
Piece of metal
When I was a kid, I (accidentally) watched a horror movie. There was a scene, in which one of characters was using a fork to take out small piece of metal from his body. It scared me very much.
After 15 years, I watched this horror again (and again - accidentally). I was very surprised that, when watching above scene, the small piece of metal was much, much smaller then I remembered. I estimate, that in reality it was about 3x smaller.
Until this experience, I though that memory is somehow 'fixed' since remembered. Was there any research conducted that would prove that memories are not fixed, not constant? It seems like feeling of fear somehow scaled up the source of fear (piece of metal) in my memory image, or some parts of memorised image grew with me. It was like my memory was 'updated'.
If memories are indid 'mutable' by experiences, the obvious question comes to mind - can suggestion influence or even change memories?