- Camels hump -

An Egyptian merchant and his son were passing through a busy market, with the man riding a camel and his son walking alongside him.
"What an unkind man," said some observers. "He sits on the camel himself while his poor son has to walk through the hot desert."

The next day, the man decided to walk, and let his son sit on the camel.
"How unfilial of the son!" cried the marketfolk this time. "Young chap like him happily rides on the camel while his poor old father has to walk. Really, the youth of today!"

The third day, both father and son decided to walk with the camel.
"What fools!" exclaimed the passersby, who gasped in disbelief. "A perfectly good camel, and they're both walking!"

On the fourth and final day, they decided to carry the camel.
"What utter idiots," cried the people, and rightfully so. "They've become the beasts of burden!"

Go figure.