Why is Wedding Guest in "The Rime of the Ancient Mariner" a sadder and wiser man after hearing the Mariner's story?I need to have three reasons. I...

When the Wedding Guest is accosted by the Mariner, he is
irritated and frightened. Once the story is underway, the Wedding Guest is mesmerised.
By the end of the tale, he is sadder and wiser. His responses - fear at being accosted
by such a strange man, fascination at such a bizarre story, sadness and reflectiveness
in reaction to the Mariner's fate and his message - certainly seem
plausible.

To me, the key reason why he is a sadder and
wiser man is that he has learnt and taken to heart the moral of the
tale:

He
prayeth well, who loveth we;l

Both man and bird and
beast.

He prayeth best, who loveth
best

All things both great and
small;

For the dear God who loveth
us,

He made and loveth
all.

It seems to be that the
main theme of this ballad is that Nature exacts its own revenge for crimes committed
against it and that it is essential to love all creatures. The Wedding Guest is a
"sadder and wiser man" because he recognises that this theme of respect for all life is
a lesson that humanity must continually relearn.