What is Odysseus’s weakness and why did Homer want to include it in this story?

Odysseus's one flaw in "The Odyssey" is his incessant boasting.  The Greeks were already well aware of his heroism and feats.  There was no need for him to recount the stories of Troy. However, for example, after he blinded Polyphemus during his escape from the Cyclopes' island, he boasted loudly about his many deeds in the Trojan War.

Also, there is a contrast between Odysseus giving credit to the gods, and taking credit for himself.  When things are going badly in front of his men, Odysseus conveniently places responsibility on the gods.  On the other hand, when things are going favorably, he quickly boasts about the whole account and designates himself as the hero!

Explanation:

i think that it is (line 11)