[Lucid:]

because the book is dark up until the last chapter where the kid turns his life around and decides that being a sick, violent punk isn't going to get him anywhere. he settles down and gets married. it's still a little bleak at the end when he realizes that his kids are probably going to turn out like he did as a teenager, but it's overall a happy ending.
American publishers didn't think that'd fly with American readers. (the book was written by an Englishman.) we're sick, messed-up folk who like dark and bleak endings. so they took out the last chapter. it was put back in later editions, but I couldn't tell which edition I was buying because it was used from Amazon. =/
it's still not a bad book without the final chapter, but I like it better with it. it feels more complete.