Who is Sir Gawain from The Power of Myth and what is their importance?

Sir Gawain and the Green Knight is a late 14th-century Middle English chivalric romance. Here is an excerpt of Dr.Joseph Campbell explaining th story's mythic significance.

Here’s a knight who really transcended the two great temptations, fear of death and lust for sex and the joys of life.....

And the moral is that the realization of your bliss, your true being, comes when you have put aside the, what might be called passing moment, with its terror and with its temptations and its statement of requirements of life, that you should live this way.