I'm not sure I understand your question, but I'll give it a shot. One of the goals of the World State is to make certain that individuals do not "feel," do not have a sense of themselves, and certainly do not have a sense that things could be "better." In order to do this, the state tries to keep everyone in an appropriate state of euphoria (this probably refers only to the Alphas since they're the ones who can "think" and we get in trouble because of it). You don't go to the movies; you go to the feelies which, while stimulating your senses, almost totally isolate you from feeling anything. The society encourages sex, but only on a sensory level; anything verging on attachment is "forbidden." Finally, should you feel "bad," you just go on a soma holiday.
I guess this brings about "happiness," but only if we define it on the most trivial of levels, as though the opposite of unhappiness were happiness. I believe that this is the whole point of depriving their society of the language, the words, that make the expression of unhappiness/discomfort/whatever impossible to express. John's problem is that he has knowledge of a world/language that is totally foreign to the inhabitants of BNW. Perhaps if you can say it, you can't experience it, and it doesn't exit. "1984" does this with "Newspeak." More to say; out of worlds. Hope this helps!