In Brave New World, why is Bernard so excited with the answers the Savage gives to his questions?

I assume that you are asking about what happens in Chapter
7 when Bernard and Lenina first meet John the Savage.  Bernard questions him about how
he came to live in the pueblo and becomes excited about his answers.  The reason for
this is that Bernard is thinking that he can use John for his own gain back in
England.

Bernard has been having trouble with his boss, the
Director.  The Director wants to exile Bernard to some island because Bernard doesn't
really act the same way as everyone else.  When Bernard meets John and hears his story,
he knows he can use John against the Director.  Because of John's story and things the
Director has told him, Bernard has realized that the Director is John's father.  In the
World State, actual biological parenthood is considered disgusting.  Because of this, if
Bernard can bring John back to England, he can discredit the Director.  Once the
Director gets fired, Bernard will be safe.  That is why he is so excited to hear the
answers -- the answers make clear that the Director is John's
father.