"Likewise, an unhealthy person who has a very easy life tends to be happy even though there are 'traumas' inside his body, and vice versa."
Having no stress coming from the outside tends to calm our body and "balance" it. Like HV said in his great post, stress depletes body from nutrients. Having no stress from the environment will keep the body healthy which affects the mind and the personality. Living in the environment where you are surrounded by healthy and successful people tends to give you the attitude to "go for it" and probably vice versa. But can one become successful in unsuccessful environment just through the attitude by not changing the environment and the care for the body. Would one fool him/her-self then ? I know the right attitude can give dopamine and adrenaline rush but it wont last long..
By the way it´s just a discussion and i´m living in great environment :)