On one hand, while Esau was extremely foolish in despising his birthright for some lentil soup, his foolishness was compounded when he failed to realize the folly of his decision, to gratify his momentary hunger,  and instead of repenting and seeking to reclaim his lost birth right, he simply rose up and walked away from the scene (Genesis 25:33-34).

To be double foolish is to not repent but to walk away.

Points to ponder:
To all who believe in Jesus and who have received him, God has given them the right to be called his children and despising our born again right by walking according to the flesh, gratifying momentary sinful pleasures, and not according to the Holy Spirit of God is foolish. But what is being doubly foolish is – when we do not repent and seek to reclaiming the joy of God’s salvation, but instead in an apostate way, blaspheming against the Holy Spirit of God, but not repenting and simply rising up and walking away. Are you and I doubly foolish?

Genesis 25:33-34 (KJV)
33 And Jacob said, Swear to me this day; and he sware unto him: and he sold his birthright unto Jacob.
34 Then Jacob gave Esau bread and pottage of lentiles; and he did eat and drink, and rose up, and went his way: thus Esau despised his birthright.