This quote comes in Chapter Six, in the letter that Chris McCandless wrote to Ron Franz. Franz befriended Chris and they became fast friends, although Chris intentionally remained detached to avoid becoming weighed down with emotional relationships. Franz was hurt by Chris's seeming aloofness towards his friendship, but Chris wrote a long letter to Franz later, detailing some of his personal philosophies and encouraging Franz to stop looking for happiness in other people and instead seek it in nature:
You are wrong if you think Joy emanates only or principally from human relationships. God has placed it all around us. It is in everything and anything we might experience... It is simply waiting out there for you to grasp it, and all you have to do is reach for it.
([sic] Krakauer, Into the Wild, Amazon.com)
This letter is vital in understanding Chris's personal philosophies. He wanted to experience the natural world as it exists without human interference, and while he valued human interaction, he also wanted to avoid what he saw as the traps of "normal" life. He expresses the opinion that many people who think they are happy are actually miserable, living the same circumstances day after day without the ambition to make changes. In Chris's opinion, if people resolved to make new experiences for themselves, they would be much happier. Franz took the letter to heart and started to travel, but sadly he and Chris never crossed paths again.