First of all, Communism is an idea that never actually worked in any country.
There are certain ideas of Communism. It promotes equality and in theory turns out to be a classless society.
To put it simply, in Communism- you contribute what you are able to do, and you get paid the same amount of money as everyone else.
What that means is, if Im able to work 7 hours, and my friend Johnny is able to work only 3 hours, we would both earn the same amount of money, say 100 dollars. In theory, people would be happy and okay with the idea that the guy in a cubical next to them in an office works half as much (because that's all they are able to work), but gets paid the same as a guy who works twice as much as him.
In an ideal Communism, there is no set line of productivity. Communism depends entirely on the people. In theory, people would honestly work as much as they are capable of working. Some can work more, and some can work less. But in theory, everybody would be honest with themselves and work as hard as they can, without slacking off. When Russia gave Communism a shot, it failed miserably. People understood that since there was no line of minimal productivity, and since there was the idea of "do what you can, get what everybody else gets", people simply said that they were only capable of working two hours, and still got a set payment of money. So in reality, people werent doing shit, producing very little, and the government still payed them.
However, the govenment COULD NOT suddenly set a line of minimal productivity, as it would go against the idea of people working as much as they are honestly capable of working. As it turned out, people saw that they would still get payed a set amount of money no matter how much they worked, so they simply did as little as possible. What Russia did do, however, was tell the people to work for longer. Russia told the people that they should work longer, as they couldnt set up a line of productivity. So, the little work that people did over four hours was now divided over 7 hours. So per hour, people were doing very little.
The theory of Communism is not meant for people. We have our own nature. Of, out of nowhere Communsm did work with humans, it would completely change our nature, and therefore change everything about humans and human history. The bottum line is that COMMUNISM DOESNT WORK WITH PEOPLE.
Communism always turns into a dictatorship-like country.
However, there is a form of Communism in the lives of ants and termites. They do what they are able to do, work hard, and share the food with the whole colony. Is this really exactly "ideal Communism"? Not exactly, but it is something. You have to remember that ants and termites have this sort of nature and are born into this. Humans are not meant to live in Communism. It doesnt work.
In my opinion, Fidel Castro had the least catastrophical form of Communism. He was able to hold his country together all this time. Are all the people happy? No. Fidel is only able to hold his shit together because he has the help of the military, and this would not be present under ideal Communism. This is just one example of what Communism turns into.