They eagerly engage in life and realize that the word “yes” has more life and possibilities in it—and is clearly so much more positive than “no.” When a client asks me to do something, I say, “Yes, I will be happy to/would love to/want to make it work for you.” I have a saying: “I never say no until I have to.” It's a great way to tell someone no (that is, if you absolutely must).
