Euclid was a greek mathematician. Some call the founder of geometry. His work," Elements" out lines five common notions that are the ground work for geometric thought.
I want to talk about the first one.
"Things which equal the same thing also equal one another."
So in other words if
a=b and b=c
Then a=c
Okay, so how does this relate to death.
Well....
death = none existence
pre-birth= none existence
so
death=pre-birth
and what were you before you were born?
Nothing.
QED
death is nothing. So why worry about nothing?
1)Euclid's Elements
https://mathcs.clarku.edu/~djoyce/elements/bookI/cn.html