Kang Ho Dong and Kim Hyun Joong turned out to be deficient in common knowledge during the latest episode of 'Barefoot Friends'.

While in the car on their way to their next destination, the two of them quizzed each other on general knowledge. On the subject of rivers and oceans, Kang Ho Dong said, "Aren't there four big rivers in the world?" to which Kim Hyun Joong replied, "Does the one in Egypt count?"

Kang Ho Dong scoffed, asking, "Why would you go to Egypt?"

"Egypt has the Red Sea, but that's an ocean," Kim Hyun Joong replied, getting confused. Kang Ho Dong continued his tirade, saying, "Isn't it the Yellow Sea?"

"I thought the Yellow Sea was a movie," Kim Hyun Joong said, alluding to the famous Korean movie of the same name. "I don't think any of us know the answer."

Their shtick continued, however. Upon arrival at the desert, Kang Ho Dong exclaimed, "It looks like the O'hara Desert" - misspeaking the name of the Sahara. After collapsing in laughter, Kim Hyun Joong said, "It's all right - at least it's not the Goo Hara desert", sending both of the newly-christened 'dumb and dumber' line into fits of laughter.