I have been studying this issue for a while. Happened too many times in my life. It's definitely not just a "coincidence" of someone's answer. Because the moment the song appeared in my mind, what the other person sang was synchronized. It can even be said that it is the feeling that is half a second earlier in my mind. One occurrence can be a coincidence, but multiple occurrences are certainly not as simple as coincidence. Before science has a standard explanation, all multiple coincidences are likely to be blind spots in current science. The time you asked the question was 13 years, and the time I am answering now is 17 years. According to the relevant scientific knowledge I have so far, some people in China have been studying experiments on "brain wave control of small animal behavior", and they have demonstrated in CCTV's "Challenge the Impossible" column that by adding some electronics to the heads of mice, The original, combined with a human electronic helmet, amplifies brain wave signals to control the mouse's walking route. Then of course we can also assume that human brain waves are very sensitive to music at close range. Secondly, it must be explained that human beings' stream of consciousness also has a cause-and-effect relationship. You will not want to sing a song for no reason. It must be the rhythm of certain sounds around you that instantly reminds you of the song. And it’s likely that people around you heard these rhythmic sounds and thought of the song. These two possibilities exist comprehensively. At present, I have no more in-depth systematic research on this. I hope that the emergence of this phenomenon is scientific rather than accidental, so that it can leave a certain factual reference for future scientific research. And I would like to know, questioner, is your IQ level significantly higher than that of ordinary people? And the brain's imagination ability exceeds that of ordinary people? Are you good at making up stories or have lucid dreams? Because these points are all my personal brain characteristics. If you are the same, you are probably a person with strong imagination and the potential of brain wave transmission ability... If this is true, I hope you can contact me by leaving a message below my answer. I have been doing some part-time research on some special human abilities.