Who is a human being? One reference is " a member of any of the races of Homo sapiens; person; man, woman, or child". Well that's an anatomical definition; perfect enough. Beyond that; the qualities we possess defines what we are. I am not making any discovery here :) Its known right? Happiness, joys, sorrows, anger, frustration, care, tenderness, love, lust, vengeance, misery, jealousy.......many many qualities; the list can go on.
The end result of these feelings are expression. I have heard expressing them does wonders; at least you dont have to carry the burden of it within you. Sometimes it can backfire; but if all you care is keeping yourself light; the backfire wont bother you. But if that is going to hit back at you; then better keep off right?
The fear of rejection or the fear of "what would they think about me?" definitely would keep us from voicing our opinions or concerns. I for one certainly think on a different angle than these two. "Did I not have that self control to handle the situation better?" always keeps me on my toes; I would better keep quiet and make my heart heavy than blurt it out and open another can of worms.
I agree it doesn't work all the time. Sometimes it works in my favor when in a day or two I realize why something happened that way or the reason behind someone's behavior. They had a reason; and I am glad I waited before I fired. Some times its odd; because the moment has passed when I could have struck red hot. The assumption that some day they will realize is a stupid one. No one does! Other times, not talking about it causes drift and bitterness within that grows like a vicious weed that can choke you up.
Anyway; this one quality sets people apart from one another isn't it? The "What if" factor. What if I told her? What if I did not tell her? What if the situation got better? What if the situation got worse? What if he understands me some day? Living in anticipation of a better situation or a favorable situation keeps us going.
"Never mind, I will be promoted next year". Only to realize you forgot to put the effort this year; you thought your last year's success will speak for your next year? Oh boy! Would it have been better to have clarified about it than assume?
Anyway, it is better to wait for the right moment to speak. Its fine to speak than holding back. But the right time gets the importance you would like to attach; meanwhile you have had time to collect your thoughts and formulate a plan to go about it.
Or sometimes its best left unsaid :)