[jester710]

I can't recall off the top of my head what exactly Jones said about the dream.

As for the other scene (warning: may be spoilers ahead), its significance is easier to understand in the book. Jones's uncle, like his father, was a sheriff; the uncle was wounded in the line of duty whereas the father was killed. Jones's character, like many people, tends to paint a rosier picture of the past than is accurate, and compares himself unfavorably to his heroes of that time. So yes, the uncle is saying that violent killers like Chigurh have always existed, and that Jones is not an inferior man for not catching him or dying trying. Jones's character spends the whole movie bemoaning the sorry state the world has come to be in, but the uncle basically tells him that people tend to compare the present unfavorably to the past, when in reality things are how they always have been, and people are people.

Also, there's a subplot in the book that's significant to this scene, and the sheriff's character as a whole, involving a commendation the sheriff won in Vietnam. I won't spoil it in case anyone intends to read the book, but it makes that scene much more significant.