# Meaning of "non se ne parla"?

I recently saw this phrase on Facebook, and I got very confused, because shouldn't it be: > Si non ne parla?I know that (or at least I was told; correct me if I am wrong) in Italian, you say: > Si non lo sa mai ("One never knows that/it")For example, this could be referring to: > Si non sa mai quando arrivano gli autobus in Italia-->Si non lo sa mai I was told that you would not say: > Non se lo sa maiSo why can't the same be said for > Non se ne parla ? Is it because the "si" is used as a reflexive here and not as the English "one" or the German "man"? But if so, what would that phrase mean? Would it mean that the person doesn't talk to himself/herself about something? Moreover, I have tried to look up the verb "parlarsene" and have come up with nothing. Please help; thanks!