system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: During conception, are there hundreds of thousands of different, unique potential people who don't get the chance to be born?
gpt
Here's the thing that gets me: it's not even enough to have a particular sperm and egg combination to determine a self. Identical twins come from the exact same sperm and egg, but are different selves. 

Even after the enormous improbability of your particular sperm and egg meeting up, your parents could still have ended up with someone who wasn't you. We really don't understand what makes a self.