As you write "50% gone" you've revealed a counting, quantitative mindset, so ask yourself if that's how you directly find life, or have you unconsciously adopted this way of thinking.
There's great news: the entirety of human history has left trails for you to follow and some of them lead to enlightenment and beauty.
There's terrible news: a lot of them lead is ugliness and pain.
All of it comes to bodily death. Is that good or bad news?
Since you've awoken to the idea of a conservation of yourself, and given that your question provides that you don't know what this means-- which indicates a normal orientation in midlife-- maybe you're ready to earnestly explore history?
I assert that science knows little about life and never will. But it can reveal opportunities and hazards.
It is in the arts and philosophy that the seeker may further prosper.
What value do you find is obtained from wealth and accomplishments?
What does history reveal about the others in your situation and with your views?
Can you engage with and trust your direct experience? How do you adapt to pain and pleasure?
This is interesting, what would you personally recommend in terms of fiction and fact/history to read to explore that. I've probably read a bit like Nietzsche, Camus, Voltaire, Stoicism, some more classical philosophy. Would like to explore more, especially history as I find my tastes have changed as I move towards middle age.
As you write "50% gone" you've revealed a counting, quantitative mindset, so ask yourself if that's how you directly find life, or have you unconsciously adopted this way of thinking.
There's great news: the entirety of human history has left trails for you to follow and some of them lead to enlightenment and beauty.
There's terrible news: a lot of them lead is ugliness and pain.
All of it comes to bodily death. Is that good or bad news?
Since you've awoken to the idea of a conservation of yourself, and given that your question provides that you don't know what this means-- which indicates a normal orientation in midlife-- maybe you're ready to earnestly explore history?
I assert that science knows little about life and never will. But it can reveal opportunities and hazards.
It is in the arts and philosophy that the seeker may further prosper.
What value do you find is obtained from wealth and accomplishments?
What does history reveal about the others in your situation and with your views?
Can you engage with and trust your direct experience? How do you adapt to pain and pleasure?
Adventure.