I don't think it's supposed to have a specific meaning. I'm going to go off the song and the video for a moment. It just shows two people- who start off innocent. Then they're faced with a choice- one chooses the road of peace, the other power. All the things the first man sees while walking are innocent things. Dancing. Music. Chalk drawings. Children playing. However the other man sees s*, advertisements, fast cars, etc. He becomes corrupt, and climbs the business ladder until he eventually becomes a president and/or other type of leader. The other man, the one who chose the path marked by the white dove, watches all these things happening. The word becomes more corrupt- shown by the black bird killing the dove, the wrecking ball breaking down a wall marked with an image of a white bird, etc. The atom-splitting on the television gets darker and more chaotic each second. Soon giant posters of the president/leader's face are posted up and cameras are set up everywhere. (Which, interestingly enough, remind me a lot of Big Brother from 1984.) The lyrics change, too- it goes from riding bikes and do-si-dos and comic books to splitting atoms and creating cures and not giving them to people. The lyrics and the video both reflect the growth of corruption in humanity. Eventually the man who chose peace gathers up all the common people and marches with them in rebellion. As protesters are shot and the skies turn black, the lyrics change, and talk about guiding missiles with satellites and sending people to prison because you don't like them, etc. Eventually the man who stirred the rebellion, the same man who chose peace and freedom, is killed right before the very man who was his friend, but chose the path of power and corruption. Hence everything changes, and the video and lyrics go back to a light and innocent "I can ride a bike with no handlebars" chorus. I see it as a warning to humanity- about what we have done and are prone to do. Like I mentioned earlier, it reminded me of 1984 by George Orwell.