Why people become so selfish that they dont mind snatcing others livelihood?

Tweet

Why are people so selfish that they are mad to acqaire and achieve things even if it means snatching away others livelihood.They get some sence of satisfaction but its disastrous for others.And ironically these achievers are the most frustrated,disillusioned,and ill health.On the other hand rural folks are very contented and are generally happy.