why do we cant stop to shake our body everytime we heared dansable music?

Haha. I'm just the same and I'm an old wrinkly!! Some people have it and many don't. You can see it on a dance floor. Some people just ooze rythm and their whole body becomes the music. I think you are like that and in the minority here and that you would stand out from the crowd on a dance floor. It's a great feeling isn't it!!