I think that this is really just an example of why Jonas is different from the other people in the society.  He is curious and he wants to know about things in general.  I think this is one reason why he is selected by the Elders to be the new Receiver.

I also think that the author has this happen because she wants to foreshadow what will happen later in the story.  I think that she wants to hint at how important the concept of release is going to be to Jonas later on.