Our identity is the illusion we create about ourselves.
We tend to think about ourselves like "this is me" "this is who I'm" and "I've always been this way" and there we are, putting ourselves in self-created cages that are made of the stories we tell ourselves over and over.
The reality is, you're not the same, nor will you ever be.
Your body is changing, the whole time, every day, every second. Every few years we become essentially new people because, in that time, every cell in your body has been replaced by a new cell. So biologically, we are made of completely new stuff.
Our identity lives only in our minds, and it is not static as lake. It is more like a river, constantly flowing, never the same.