Why say Yes when you want to say No?

One of my college teachers used to keep repeating this and sometimes used to write on the board as thought for the day: Don't say Yes when you want to say No.

I have had a number of experiences where I have said yes to things I didn't want to do. I am sure many others would have the same experience.

After doing things like this, I used to end up feeling frustrated with myself for
a> not having the ability to have said no (some times when I should have told on the person's face) and endend up with extra work/unwanted dinner/unwanted company etc.
b> for allowing the person to take me for granted and risking a similar thing again.

By some chance if I had said "No" to something, I would sit fretting and feeling bad about why I told a "No". What would that person think of me. And if the reason/pretext/excuse I have given is not strong enough, what if I fall flat while convincing. Note that I had to give some pretext to say No, never that I don't want it this way and so my answer is No.

I guess a lot of times, your childhood experiences play a very important role. The way you have been brought up and whether you had enough freedom during your childhood days to express yourself, how your minor mistakes have been treated by your parents, elders etc. Were you reprimanded for every small mistake or treated like "prince/princess" of the house.

At least in my case, I was never treated like the princess of the house. And during our childhood days, we children had to keep our mouth shut in front of elders. And accept and abide by what ever was told to us. After all, that was the sign of a good, obedient child in those days. So, even to express simple desires or feelings, we children used to hesitate. I guess the same hesitation got carried forward to teenage and adulthood. And somewhere down the line, we forgot what we really felt like and whether that feeling (may be anger, jealousy, hatred etc.) was even justified.

So, even after marriage, the same thing continued. From "Malini, wear that pink dress..." but no, I want to wear the green dress to "Malini attend this party with us", but no, I don't want to attend, I have an office call to take.

I have found that some people are adept at getting a "Yes" out of you even when you don't want to say so.
Here I am not talking about office life scenarios because that is totally a different story. Whether you want to tell a Yes or No, depends on a lot of things in office life. And needs to be handled differently. What I am talking about here is the personal life where your own friends, family and acquaitances are involved.

After having said a yes and allowed yourself to be taken for granted you end up feeling resentful and the same feeling builds up each time you are taken for granted and finally one day you can take it no more.
Instead of bringing yourself to that stage of desparation, it is better to say No and risk being in the bad books of that person especially when the demands are not justified.

It is only now when I sit and analyze and try to understand my own feelings, that my thoughts are clearing up and I realize that some of the feelings are justified but need to be handled.
As I introspect, I realize that many times, I have told yes because
1> I am not clear with my own thoughts and don't know what I wanted.
2> Fear of rejection in a group and so say yes to every unwanted dinner, picnic etc. etc.
3> Fear of hurting another person's feelings (don't know where from I got this) and fear of being the (not called) "bad person".

Point 3 must have come from our moral science stories which we read during school days. I am not saying that moral science stories have given us a completely skewed view of what is wrong and right, but I feel many things need to be seen in right context.
As I analyze and look at the whole picture, I begin the understand that by saying "no" you are not being "bad" or doing so because you want to hurt the other person.
Slowly as I understand this, I can now say to No to things I want to say No. Of course, I still do believe that one has to be tactful and graceful when refusing anybody. A direct on the face "No" may not be appropriate.