Some people have trouble saying no. They say yes to everything they are asked to do. Have you ever seen the movie Yes Man? People in real life are kind of like that who have a problem by saying no.
I use to be a Yes man. I would say yes to everything and then quickly realized I would get way too stressed out. Now I'm doing a lot better at thinking about things when I'm asked to do something and I will think if I really want to do it or not before simply saying yes.
Good movie also and I did like it. For me I'm in the middle I say yes to things then again I say no to things. Most times I have no options to do it even when I don't want to do it.
After high school, I had learned to say no to people's motion that I don't like. Maybe that was a sign of maturity on my part or perhaps that was a rebellion of some kind. I used to be meek and mild, obeying and agreeing to people. I think that was due to my family because I am the youngest in a brood of 12. Now I am firm with my decision and I say no without batting my eyelash.
Saying no has always come easily to me. In real life I've always been anti social and I have had control issues in the past. I was an all or nothing guy.
This is a lesson I've had to learn myself. I've learned how to say "no" more and more over the years. There have been many times where people have asked to borrow money and I've had to say "no" to them. If I hadn't, I'd be living in a cardboard box under the bridge by now.