Comment by IggleSniggle

It generally means that while you live somewhere permanently with no timeline on returning "home," you do not allow yourself to think of your new country as "home."

It comes across as a refusal to immigrate. It means that what you care about is that you are no longer living "at home," rather than caring about assimilating with your new home.

It's like going to a new place and identifying yourself as an "emigrant" instead of an "immigrant."

"Patriation" is about giving away authority so that the other country assumes authority. "Expatriate," then, would be that authority of the old country no longer applies, with no acknowledgement of your new circumstances.

Oh here's a good one; what if you got married, divorced, and married again? You would be an ex-husband or ex-wife, and it would be entirely appropriate for someone to refer to you as such in certain contexts, but it would be really off-putting...especially to your new spouse.

Imagine introducing yourself as an "ex-husband." If you're with a bunch of your ex-wife's old friends and associates, then it might make sense to introduce yourself this way under some circumstances...but usually, even then, it would be far more polite and in better taste to introduce yourself in some other way.

Much better to clarify your former relationship only when it's pertinent, and maybe even then "we lived together for awhile" might be a gentler framing. Otherwise, you are simply drawing attention to your divorce, and to what purpose?