Mysteriously Funny Gorilla

Here's a joke that made me laugh:

This guy takes a gorilla out golfing. At the first tee the gorilla says, “So what am I supposed to do?” The guy says, “You see that green area about 400 yards from here? You’re supposed to hit the ball onto that.” So the gorilla takes a club and whacks the ball and it soars up into the sky and drops down neatly on the green. The guy tees off and makes about 150 yards, so he hits an iron shot and then another iron shot and finally they arrive at the green. The gorilla says, “What do I do now?” The guy says, “Now you hit it into that cup.” The gorilla says, “Why didn’t you tell me that back there?”

This wouldn't be particularly funny if instead of a gorilla it had been another person, or even the Archbishop of Canterbury. It's funny because it's a gorilla. But why is it funny because it's a gorilla?