What would be the advantages and disadvantages of spending two solitary years in a natural setting, like Thoreau did in "Walden"?

Rudyard
Kipling's poem "If" reflects upon the need for a balance in one's life, attachment
with detachment, righteousness without self-righteousness, etc.  So, too, does Thoreau suggest a
balance in one's life when he writes in ","

I
went to the woods because I wished to live deliberately, to front only the essential facts of
life, and see if I could not learn what it had to teach.... I left the woods for as good a
reason as I went there.  Perhaps it seemed to me that I had several more lives to live, and
could not spare any more time for that one.  It is remarkable how easily and insensibly we fall
into a particular route, and make a beaten track for ouselves.

So, to spend two solitary years in a natural setting seems a bit beyond moderation. 
Yet, some time alone away from the "world [that] is too much with us" as Wordsworth
wrote, would probably be good for most people's souls.  Certainly, communicating with Nature and
with one's inner self is always healthy.  Retreats...