Full Idea
Egoism, and the fear not of near but of distant death, and the regret that so much of one's life should have gone by - these are not, I think, wholly natural or instinctive. They are strengthened by a false belief in stable identity.
Gist of Idea
Concern for our own lives isn't the source of belief in identity, it is the result of it
Source
Derek Parfit (Personal Identity [1971], §6)
Book Reference
'Personal Identity', ed/tr. Perry,John [University of California 1975], p.220
A Reaction
This raises some very nice questions, about the extent to which various aspects of self-concern are instinctive and natural, or culturally induced, and even totally misguided and false. I can worry about the distant death of my guinea pig, or my grandson.