Proverbs 12:15 The way of a fool is right in his own eyes: but he that hearkeneth unto counsel is wise.
16 A fool’s wrath is presently known: but a prudent man covereth shame.
Here we see two aspects of a fool. Remember we have already seen a fool lacks understanding. This tells us they are self centered and they think the whole world revolves around them.They think to highly of themselves just like Lucifer did. In the next verse we see a fool looses his temper easily. They usually get mad before they even know what the problem is.
On the other hand we see again that if we listen to wise teachings of the word of God we ourselves will become wise. And with this wisdom we learn to control our anger and gain the ability of self control. We can even ignore an insult. We need to strive to gain as much wisdom and knowledge of the word of God that we can so we do not make foolish mistakes.