Here is a marvelous explanation on yesterday's Gospel of the workers in the vineyard:
Let us imagine that one day all the inhabitants of the world would assemble to put into effect this sharing of goods; and that in fact each person, granted that the world is very big, received an exactly equal portion of the wealth existing on earth.
Then what? That very evening one man might way, "Today I worked hard; now I am going to take rest." Another might state, "I understand this sharing of goods well; so let's drink and celebrate such an extraordinary happening." On the other hand, another might say, "Now I am going to set to work with a will so as to reap the greatest benefit I can from what I have received." And so, starting on the next day, the first man would have only the amount given him; the second would have less, adn the third would have increased his.
Then what do we do? Start redistributing the wealth all over again? Even if everybody began to work right away with all his might and at the same time, the results would not be identical for all. ...To continue the argument, even if there were only two persons in the world, they would not succeed in maintaining absolute equality; for in the whole universe there are no two things completely identical in every respect. (Maximilian Kolbe, + 1941)