You say "But we will all find out, one day."
I think... maybe we already know? Before I was born, I did not exist. When I die, I will again no longer exist.
If Earth is ~4.5 billion years old, what was it like waiting for all the things to happen before I could be born to crawl upon its surface with a diaper on, grow up and ponder life, eventually find this comment on HN and reply to it?
By not existing before we were born, do we already know what it's like to not exist after we die?