I think: lose enough ego and entitlement, and you can not only find peace with death but even see it as a truly "happy ending" given the wondrous experiences of the uncountable people that will come after you (and what a petty, selfish distinction whose experiences those are is).

But that's not easy. It seems to take years of thinking about death almost daily and thinking about space and time[0] and history and stuff. And maybe psychedelics, although I never tried those yet.

0: https://youtu.be/5TbUxGZtwGI