mankind.. a weak fighter

it just crossed my mind when I was travelling in a tram and saw a guy with a shopping back, smoking a cigarette and trying to drink a coke at the same time. I was askin myself, why is this guy doing it and then the answer just popped up in my mind. Our mankind is a weak fighter, we are no more questioning ourselfs for functionalism, but we are eaten, honestly, we let ourselfs be eaten by our weaknesses. Lets take the coke for example. It is full of sugar and other ingredients our body does not require (as we are feeded well for imporant ingredients in other meals). Why do we not drink 'just' water? It would be just enough, it gives us what we require, but nowadays it is not enough, we do not think more about what we need, but what we want, what for we have a taste, what would satisfy this and that and we are becoming more and more dependant on such way of thinking, changing the world to serve us in this way. But the world will not serve us forever..