The fool has no genuine interest in understanding others or truth — only in self-expression. 'That his heart may discover itself' means the fool speaks to reveal and promote his own opinions, not to gain knowledge. This is the opposite of wisdom, which listens and learns. Foolishness is ultimately self-centred.
Memory phrase: Fools love only talking.
Talk about it: Why is listening more important than just talking?
Prayer: God, help me love learning more than just talking.