Movies
Sick Boy's always been lacking in moral fiber.
— Renton • Trainspotting

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker delivers a sweeping judgment of Sick Boy's character, presenting a lack of moral strength as a longstanding trait. The word always makes the criticism sound settled and familiar. The concise phrasing gives this unflattering assessment the force of something the speaker considers already established.
Context reviewed