Not too long ago, I was reading a book called The Man Who Mistook His Wife for a Hat. Written by Oliver Sacks (a professor of neurology and psychiatry who also wrote about the effect of music on the human brain in a book called Musicophilia), the book is a collection of accounts of patients suffering from various right-hemisphere brain disorders that the author came across during his many years of psychiatric work.

I found most of the short stories fascinating, and a few of them terrifying. One chapter told the tale of an older woman who had songs “playing” uncontrollably in her head all the time. The titular story described a man who, although he could see just fine, had a condition where his brain couldn’t take multiple visual cues and combine them into concepts; he could see a nose, eyes and a mouth, but he couldn’t comprehend what a face was, and could only recognize people’s identities after he heard them speak.

One of the more frightening stories was about a woman who spontaneously lost her sense of proprioception, which basically meant she no longer felt as though her own body was an extension of herself. Formerly a very athletic person, the patient could now only walk if she was looking at her own feet, could only use her hands if she had them in her visual field. A frightening prospect, even if it’s unlikely to happen to any of the rest of us.

But the scariest of all was the story of a man who suffered from amnesia to the extent that he hadn’t formed new memories in decades. Much like the movie Memento, you could have a conversation with him, leave the room for ten minutes, and then return only to find that he had no recollection of meeting you before.

Sacks describes seeing an underlying sadness in this man, who couldn’t have any real idea of the affliction he had, but appeared to have a vague sense that something was constantly amiss in his life. Though in his sixties, years of heavy alcohol abuse had erased his memory since he was about 17. As a result, he thought he was still in the Navy, and seeing his image in a mirror would only cause him to freak out, wondering who the old man was in the reflection.

It got me thinking a bit about what makes me “me” and what makes you “you.” What is our identity if it’s not our own memories? Do we not become the people we are through learning from mistakes, growing with experience, and fulfilling our lives with the adventure that is living? What is left of me if my memory is taken away?  What meaning could my life have if I don’t really know who I am?

There are many horrible diseases that can do horrible things to the human body, but the ones that scare me the most are the ones like Alzheimer’s that steal your own memory away. Because I realize now that my memory is my very identity. Taking that from me is as good as taking away my entire life and everything I’ve worked for.

Value greatly the memories of your life, the good, the bad and the mundane. Without them, each day is starting from scratch.