Treat people in the way you’d like to be treated not in the way they treat you!

In my trials to follow the manners of a true Muslim, I tend not to judge others, I try to find excuses for them, I try to see things from their perspective etc. Also from my readings in management and communication skills, it is always mentioned that this is the best way to deal with others and have successful communication with them. The problem is that not all people follow the same attitude and though I may be doing my best to deal with people in this manner, I many times get shocked with their mean attitudes. At the same time I find others around me, who doesn’t try to presume the good intentions and see things from others perspective, are less socked because they saw it coming or at least have always presumed the worst scenarios. I began to doubt my policy in dealing with people, though I don’t feel like changing it because I think that it’s a good policy after all and presuming good intentions is better that presuming bad ones because by then dealing with and trusting others would be really hard and life would be miserable. So should we just keep the good intentions and try to see things from others perspective, or should we do that while being cautious to avoid latter shocks or would it be easier to presume bad intentions and worst case scenarios from the start?!