Have to agree with you on this as well @juvyjabian. Sometimes we just can't explain human characters by itself. Some were born strong-willed, stubborn. I've seen people, a man, not a kid, who says no to everything as well. Some would just submit to the people around him to gain friends, and learn to say yes to everything.
Hopefully this post reaches to somebody who needs help saying "NO", and hard-willed enough to follow through all the steps above. Nice post @sirwinchester
Others would take NO as total rejection, which is not true. People just have to learn that not everything they wanted can be given to them. Its a fact that we are not in control of everything.