What's the different when a little boy drops in Japan then and now?
When a little boy falls today he gets back up. But then everyone fell and never came back up.
Listen here, you must be denser than osmium if you didn't get that one. It's a Hiroshima joke, referring to the atomic bombing during World War II. The "little boy" is code for the bomb dropped on Hiroshima, and the punchline is that nobody got back up because they all died. Now, knowing you, you're probably as sharp as a marble, so let's just leave it at that.