In The Canterbury Tales, what qualities does the Knight posses that differ from those you might expect to find in a veteran solider?

First, to answer this question, ask yourself what traits
you would consider typical of a veteran soldier. Personally, I'd think of an experienced
soldier as tough, maybe a little bit jaded, and perhaps
world-weary.

Then, think of traits you derive from the
prologue's description of the knight. The most memorable phrase Chaucer uses here
is:

And though
so much distinguished, he was wise
And in his bearing modest as a maid.

He never yet a boorish thing had said
In all his life to any, come
what might.
He was a truly perfect, gentle
knight.

In the above passage,
the knight is proscribed several traits- wisdom, modesty, perfection, and gentility.
Would you compare a soldier to a maid, as Chaucer has done here? Wisdom, I'd say could
certainly be gained in battle. Chaucer also indicates here that the knight has never
said anything rude or crude. When thinking about a soldier at war, do you usually think
of politeness of manner?

 I think this description is
atypical for a soldier. Gentility is probably not something I would associate with a
soldier who has been through many battles. In fact, I'd think of a rough, tough manner
instead of a gentle, chivalrous one as the night is proscribed.