TV
Oh there you go again - mistaking me for someone who gives a damn! Who cares if you're fat or thin...who cares if you live or die?!
— Nurse • Absolutely Fabulous

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker snaps that the other person keeps mistaking them for someone who cares, then rattles off that they couldn't care less whether the person is fat, thin, alive or dead. It's a theatrically callous put-down, played for laughs through sheer, sweeping indifference.
Context reviewed