Chuks,
What is the definition of "Last Expat" ?
I believe a discussion of "limits" as used in the study of Math (s) applies here.
A limit being defined loosely as a value which one can approach but cannot achieve applies here.
If one dons Native dress, marries a Nigerian, raises one's children in Nigeria, takes the employ of a Nigerian firm, has a Nigerian drivers license, a Nigerian Flying License, holds country club membership in Nigeria, and as some have assumed a leadership role in a village.....when does one become a "Nigerian"?