On a visit to my then 88-year-old mother in Chattanooga a few years ago, she entertained me with a song she had learned more than 80 years previously, "My Grandfather's Clock":
"My Grandfather's clock was too tall for its shelf, so it stood 90 years on the floor..."
The words came tumbling out, the entire song, without missing a beat. How? How can the words and tune of a childhood ditty still be in there, woven into a tapestry of neurons, able to be instantly extracted and sung, without erasing -- like Googling the internet?
There may be as many as 100 billion nerve cells in the human brain, and each one is connected to thousands of others. Memories are stored as electrical and chemical changes at the synapses where cell communicates with cell. A lifetime of experiences scribbled into flesh, and when I visit my mom again in a few weeks time the song will likely be as fresh as ever.
This is the self: a vast web of synaptic connections, unconsciously assembled over a lifetime, utterly unique, almost miraculously complex, infinitely precious.
"Ninety years without slumbering, tick tock tick tock. His life seconds numbering, tick tock tick tock . . ."