Yuyutsu,

If reincarnation exists we can't all be reincarnations as there are more people alive than of yore, so where do the numbers come from and how does one tell if one is in a first existence?

Dear Is Mise,

I suspect there are realms out there that we can't even
begin to imagine.

Dear Is Mise,

A human birth is very rare: as Foxy said, there are many other realms of existence, some "higher" (more power and pleasure) and others "lower" (more helplessness and suffering), but being born as a human, with the right balance between power and helplessness, pleasure and suffering, is nearest to the "Exit" sign and practically the only state where one can escape the cycle of birth and death and reunite with God. If one is now a human, one must have worked hard for perhaps trillions of incarnations to deserve it, so I don't think that any human here can be "first existence".