It seems there were two frogs sitting on a lily pad, when all of a sudden, a fly came along. One frog put out his tongue, ate the fly, and started laughing hysterically. Soon the other frog joined in the laughter.
Later in the day, the other frog ate a fly and the two frogs burst out in laughter. As time went on, the frogs enjoyed the flies so much that the sight of a fly would cause them to double up with pleasure (if it's possible for frogs to double up!). But of course, the most pleasure came when the fly was actually eaten.
A third frog hopped up to the first two and asked what was so funny. The first frog answered "Time." "Huh?" asked the third frog. The second frog explained:
"Time's fun when you're having flies."