Fake Friends

So now Dave Jensen and Lee Strunk are supposed to be BFF. I still don't understand why they couldn't just be friends in the first place, but whatever. Anyway...in the last line of the chapter the book reads, "Later we heard that Strunk died somewhere over Chu Lai, which seemed to relieve Dave Jensen of an enormous weight," (page 63). I do not understand why they refer to each other as being some sort of a burden. If they are friends now and have each others' backs, then why would their friendship feel like some sort of weight they had to carry around? If the whole time they were acting as friends just for selfish matters, or in other words to save themselves, then why not just be strangers? I am so sick of people being friends for fake reasons. I thought that kind of stuff only happened to kids in elementary school and high school. I am so glad that I have had the same set of close friends my entire life. I like knowing that I can trust them with anything; I have no idea what I would do if I had to worry about a "friend" the way Strunk and Jensen worry about each other in the book. These past two chapters are rather annoying!