Just because you're familiar with something doesn't mean you know everything and there isn't anything left to learn. Sometimes it's interesting to ask basic questions just to see how the answer is made. Maybe it's not the facts of bin laden that was interesting to the kids doing the search but the portrayal of bin laden. Perhaps different sources had different answers to this question and that was the interesting part.

And even if a child or an adult decided to do some research about bin laden (or anything else!) what in the world is the problem? This is NOT evidence of gross ignorance, this is evidence of learning. This is ridiculous, why am I even replying.