Tears are the most sincere way to express sadness and be honest with ourselves. Since I've grown up, I suffer from being unable to weep – I can do it very seldom. Weeping helps you releasing and feel everything more clearly (pay attention: I wrote FEEL, not understand), no matter if you're alone or with someone. Sometimes the others (especially the ones caring of you) will worry about you or feel simpathetic when they see you weeping; this may help or annoy you as well, it depends on... oh, I don't know.