I do not think that this statement is literally true, in the sense that giving your all to something is not exactly "satisfying" while the experience of knowing you did your best can occasionally give you a boost, the true satisfaction is not about how much effort you gave, but about overcoming the difficulty. Whether you give 59% or 120% to a task, overcoming something that was difficult is always satisfying.
Answer: Marx thought that the economic system of communism would replace capitalism. Communism is based on principles meant to correct the problems caused by capitalism. The most important principle of communism is that no private ownership of property should be allowed.
Mental breakdowns happen to ppl who have something mentally wrong with them and they would need help with that. It is common with serial killers and first time murderers.
Answer:
the bartering of goods for each other