People who are stubborn or selfish how to tell them anything?

Singapore
May 6, 2008 3:41am CST
I was working on web project with a friend who wanted to start an online busniess. So i kept telling that if he does some of things that he wanted to he would lose out. So we had a long chat, in the end he was still stubborn and wanted to do things his way. I have quite a few friends and relatives who are stubborn. When i try to explain, they seem to be listening. In the end they will still go on with what they want. Such thinking affects people around. Like for me if i am going to be stubborn about something i would lay down the facts and figures. Even if i ask them to do the same , they would simply say "it will work out cause i have done my homework". So how do you get around with such people? For me i let them have thier way. Do you have any method that could help to tell them to stop being stubborn? Share your experiences and thoughts?