What are some quotes from Into the Wild that support the idea of McCandless being ignorant?

Whether or not Chris McCandless was completely ignorant and very lucky most of the time
is up to each reader to decide.  There are going to be readers that find McCandless inspiring,
brave, and highly intelligent; however, I do believe that Krakauer provides solid evidence near
the end of the novel that supports the idea that McCandless was ignorant of how seriously
dangerous his sojourn into Alaska could be.  Krakauer includes some letters that he received
from readers of his earlier articles about McCandless.  One of those letters includes the
following quote.  

His ignorance, which could have been
cured by a USGS quadrant and a Boy Scout manual, is what killed him.