The Greek Orthodox have an old and wonderful tradition, the day after Easter is devoted to telling jokes. It's to imitate the cosmic "joke" that God pulled on Satan in the Resurrection. Satan thought he had won, and was smug in his victory, smiling to himself, having the last word. So he thought. Then God raised Jesus from the dead, and life and salvation became the last words. It's the cosmic plot twist to end all cosmic twist.

---

Note: Beleifnet has a good article on this.