The words we did not say (but we think??)

Since I've been left alone in this blog, I've a lot of lonely arguments to populate my mind. One of them is the words I don't say (but I think). Sometimes is an act of intelligence and sensitivity not to say everything we think, and I totally agree with that. Better the silence than an embarassment. Furthermore there are different contexts and even if we are not shy, we may be totally closed in some situations.

But I just wonder what the effect would be, if I just say what I think in these occasions when instead I really feel I've to keep my mouth shut. When, even if I want to say something, the voice does not come out. Silence is also a missunderstanding sometimes.