The Brave New World is essentially the world, as it would exist if people slowly began to remove any types of restraints from their lives. It is a world with almost total freedom given to its inhabitants. Sexual promiscuity is encouraged throughout life, giving no restraint in that sense, when something is old, people will just simply replace it, the inconvenience of actually having to know how something works is removed and instead people only have to know simple operations (pushing buttons, knowing numbers, etc.) in order to do any real “work”, and all games are extremely interactive to make people do something at all times. Then, for everything that cannot be completely controlled and may complicate life, citizens have soma which can make them happy again and completely oblivious of the outside events. The point that Huxley is trying to get across by this is that while we would assume that a world with total freedom and no work would be a utopia, it can only survive through ignorance and reverting to an animalistic state, only truly unique due to the fancy technology that they possess.
It is interesting to note that the world is meant to be a utopia where there is only pure pleasure and bliss, but that bliss can only be obtained through ignorance (“ignorance is bliss”); ignorance not only towards knowledge, but also towards emotion and restraint. The people of the Brave New World are all pushed away from emotion throughout their lives, initially by making them all a part of a national “collective population” rather than a part of a small family. Then, by supporting sexual promiscuity, societies looks down on monogamy and therefore love at all, which is exceedingly difficult to practice if one is changing “lovers” every week. Then, if a citizen does happen to feel emotion, it is seen as being abnormal and frightening, and soma is used to dull the senses and make the person happy again (though it is debatably whether they are happy in the same way that we today can be happy, seeing as their senses have been dulled. It is more likely that the people just do not feel sorrow or anger of fear).
It is also interesting how “soma” is the name of the Hindu god/drink (soma is both the god and the drink at the same time), which provided “spiritual excitement” to its drinker, and Hinduism is very supportive of the Caste system, such as the one used by the Brave New World. The Caste system also shows how the citizens are ignorant. Obviously the same joy that a delta feels is not the same as the joy that an alpha feels, since a delta gains joy from seemingly plain things, such as the roof. Since the deltas are experiencing happiness from things that do not “deserve” to produce happiness, this would mean that the alphas could possibly be ignorant to “true” happiness also (or, quite possibly we today are ignorant to true happiness as well).