When Montag gets out of the river, why are his senses so acute?

I think that there are at least a couple of reasons why Montag's senses are so acute in this situation.

First, it is often said that your senses get more acute when you are in a dangerous situation.  I do not know if it is true or if you just feel that way.  At any rate, he is in a very dangerous situation and will therefore be more aware of things.

Second (and this seems more important to me) he is now really alive for the first time in a very long time.  He has crossed the river and has been reborn in the country.  This is a place that is so different from the city and its society.  So he is experiencing all these things for the first time.  He has gotten out of the stifling society he wants to destroy and is now free.