Explain-"perhaps a huge silence might interupt this sadness of never understanding ourselves". what is the source of this sadness and how one can be free from it?

The poet feels that today, people are so engrossed in keeping their lives moving.. That no one has time to think about themselves or other around 'em. This is the SOURCE of this sadness. He believes that if we observe a few moments of silence, it would unite us in a strange silence and help us understand ourselves better and also free us from this sadness.