What’s the point of the camel overtaking joke?

In the boundless desert, an old man was riding a camel on the road.

After a while, the old man saw a car coming from behind. The old man kept waving in front of the car. The car stopped and the old man said to the driver: Hello! "It's too hot to walk in the desert. Can I hitch a ride and get some air conditioning?"

The driver replied, "Okay, you can! But where's your camel?"

The old man said: "It doesn't matter. He just needs to follow your car."

The driver said: "Okay, come on up." ”

At first, the driver drove at 40 kilometers (per hour). From the rear mirror, he saw that the camel was keeping up easily. So he accelerated to 60 kilometers (per hour) and looked at the camel. Can he still keep up?

So he accelerated to 100 kilometers per hour, and then asked the old man: "Is it really okay for your camel to follow you? I saw that it had bared its teeth and stuck out its tongue..."

After hearing this, the old man asked nervously: "Where is his tongue sticking out? "

The driver said: "On the right! "

The old man said: "Drive the car to the left, pay attention, it is about to overtake!

The funny thing is how can a camel overtake?