Originally posted by: MemnochTheCaT
I'm not underestimating old people lol .. just that MOST of them aren't like the 3rd. Sasuke's grandparents just stood there ... REAL intimidating huh?
As I said, the scene with Itachi killing his grandparents and the rest of the Uchiha so easily was an illusion that he made up for Sasuke just to torture him, not what actually happened.

We don't know what really happened in his fight. I suspect that everyone was so shocked to see their grandson, nephew, whatever relation come at them with a knife that they weren't really able to fight back decently before being killed.

I agree that instead of a test of physical strength it may have been a test of mental strength, or "coldness" as Barles said. Although killing your entire family just to show what an emotionless badass you are...damn. And I STILL don't know why he let Sasuke live.