Themes
The best thing about pain, it tells you you're not dead yet.
— Master Chief ‧ G.I. Jane

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Pain is given a grim consolation: feeling it means that life continues. The statement does not make the sensation pleasant, but finds a reason to value what it indicates. Its blunt comparison sets suffering against death and claims a small advantage for remaining alive.
Context reviewed