One of the more persistent criticisms of communism is that communism assumes or requires that individuals sacrifice their individual self-interest to the good of society. All of Ayn Rand's criticism of collectivism (under which she includes both communism and fascism) depend on this fundamental view of communism.
This view is fundamentally misleading and the criticism the demolition of a straw man.
It is a scientific truth about human minds that individual people will choose among the available options determined by the predominant political-economic context to maximize their self-interest. If there is any "fundamental" component of human nature, this is it, and communists can ignore this scientific truth no more than we can ignore the law of gravity. However, the political-economic context plays a critical role. Furthermore, there is no intrinsic limit on how far people can look ahead to the consequences of their actions, and how broadly they can construe "self-interest".
There is a very limited sense in which a collectivist political-economic ideology requires individuals to "sacrifice" their self-interest. This sacrifice is best illustrated in the Prisoner's Dilemma. The best outcome in a Prisoner's Dilemma for an individual is where she "defects" and her opponent "cooperates". Communism demands that individuals "sacrifice" this outcome and instead end up with mutual cooperation. But practically speaking, absent coercing either party, the outcome of Prisoner's Dilemma is mutual defection; Communism therefore demands that individuals choose mutual cooperation over mutual defection, to the benefit of both individuals. Essentially, Communism typically deprecates the benefits of exploitation in favor of the benefits of mutual cooperation.
There are two ways to promote mutual cooperation. The first is to change people's individual psychological makeup so that their feelings of empathy make defection intrinsically negative: to "change the game" from within. The second is to coerce mutual cooperation, to impose external penalties for defection, making defection extrinsically negative: to "change the game" from without.
Exploitative political systems such as capitalism "change the game" from without, but do so asymmetrically. They coerce cooperation from one party (the ruled class) but do not coerce cooperation from the other party (the ruling class). Under every ruling/ruled class political-economic system, the vast majority of the social, political and psychological constructions of that society exist to justify the asymmetric changes — established coercively — to economic decisions that follow the logic of the Prisoner's Dilemma.
To the extent that asymmetric, exploitative changes to Prisoner's Dilemma economic decisions are entrenched in our society, it is true that communism demands that some people — those whose reward is the outcome of exploitation — sacrifice their overall, actual self-interest for the good of society, with only the lesser reward of mutual self-interest. Such individuals already lack some degree of empathy (if they had full empathy, they would not be exploiting others); and they have internalized at a deep level the ideology and propaganda that justifies exploitation. Thus we cannot expect those presently enjoying exploitative privilege to simply abandon that privilege out of the goodness of their hearts and begin to act for mutual benefit.
Can such psychological and social constructions that promote mutual cooperation exist? Of course: they already exist. All instances of teamwork and cooperation employ psychological constructions that promote mutual cooperation and deprecate exploitation. I can, for example, pool my capital with my wife, without worrying that she'll "defect" and run off to Rio with our combined savings. Such psychological constructions even work at the highest, most abstract levels, as when people help others on the other side of the world after a natural disaster, rather than exploiting their extraordinary misfortune to scoop up some more slaves.
Social and political constructions also already exist. Both the capitalist class and the working class do a lot of mutually beneficial trading amongst themselves; exploitation is typically embedded only in relations between the capitalist class and the working class, and really only in some relations.
So, in essence, communism does not ask for anything substantively new: it asks only that psychological and social constructions that already exist be promoted and made more pervasive.