Maybe you have made the same experience in life: there is a topic, something that is on the table and you feel like it would be great to speak about it. 

But the other one is not talking about it. 
She/he might even ignoring that you are trying to reach out to clarify things. 

My experience has taught me that there are only two possibilities why this is happening:
1. Either the subject means nothing to the other person, she/he just doesn’t care.
2. Or the subject means everything to the other one. So much that she/he cannot speak up and about it.