Characters
Well, my days of not taking you seriously are certainly coming to a middle.
— Mal · Firefly
Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Mal seems to be approaching an admission that he has underestimated someone, then replaces the expected ending with a middle. His dismissal is still going strong. The polite-sounding setup makes the refusal to take the other person seriously even sharper.
Context reviewed