Memory is everything.

That’s my starting point. Possibly an infuriatingly simple answer to an extremely complicated question.

What makes me me? My body changes. My opinions change. I get older. I learn things, forget things and occasionally develop the sort of idea that makes somebody else say, ‘Oh, bloody hell, not another website.’

And yet there’s a thread running through it all. Yesterday’s experiences shape today’s reactions. The person I am now has a history. I remember things, and other people remember me.

That thread is memory.

A person isn’t a frozen object.

We don’t stay identical from one moment to the next. We develop. We make mistakes. We change our minds. We pick up phrases from friends, habits from family and jokes that become part of our personality.

If identity meant never changing, nobody would remain themselves for very long.

Perhaps being yourself is more like being a story: you can add chapters without becoming a completely different book.

But memory isn’t the whole story.

Two people could remember the same holiday and still tell completely different stories about it. One remembers the scenery. The other remembers the car breaking down. A third remembers a sandwich.

The events are shared, but the individuals are not interchangeable.

So I’d add another ingredient: difference. Character. The particular way a mind responds to what happens.

Memory gives continuity. Difference gives that continuity a personality.

And what happens when someone dies?

There’s the difficult part.

A person’s experiences don’t all vanish from the world when they do. Their words, mannerisms, kindness, terrible jokes and ways of looking at things can survive in the people who knew them.

That isn’t a claim that memory defeats death or proves an afterlife. It’s something simpler and, to me, meaningful: a person can continue to influence the world through the people who remember them.

‘Gone but not forgotten’ is more than a polite phrase. Memory is one of the ways human beings remain part of each other’s lives.

The thought to take away

If memory shapes identity, and identity changes through experience, then perhaps a self is something that develops — not something that arrives fully assembled.

Which raises a new question: what happens when something made of silicon begins to build a history with us?