Where did "watermelon" flavor come from? (Because it sure as hell doesn't taste like watermelon.)

If someone were to give you a watermelon flavored Jolly Rancher, but didn’t tell you what flavor it was, you would probably be able to identify the “flavor” as soon as you put it in your mouth. “Watermelon flavor” is fairly standard, but does it taste anything like a watermelon? No, it doesn’t.
And it’s the same thing with cherry, or banana, or grape, or most anything else.

How did candy companies originally decide that certain flavors would represent certain fruits, even though they taste nothing like each other?