The verbalization of internal thoughts facilitates social interaction.
From a purely goal-oriented perspective, one's dialogue must be effective enough to communicate an idea that advances one's motives. From the basic commands, to the uses of gossip in search of self validation, to the spilling of affection vocally expressed, to the discussion of personal theory and perspective in order to gain a higher understanding- conversation aims to bring a means to an end, no matter the subtlety.
Yet in this day and age, my generation seems to be sorely lacking in the art of effective conversation. We can not clearly communicate because we are not sure what we are communicating, and why. We do not exercise enough awareness during our thoughtless dialogue.
The shibboleth holds true- we do not think before we speak.
Like music, art, and the buildings we occupy, clarity and function are a product of a harmonious balance between substance and space. Emptiness and fullness. Nothing and something.
Good conversation requires clarity and function. Good conversation needs the silence, the spaces between words and ideas, in order to convey those notions more clearly. Substance needs space in order to expand; confinement only brings about the inconveniences of clutter. Clutter tends to accumulate.
Saying too much is a practice in excess. Excess is not abundance. Excess neglects the conveniences of simplicity. Excess dialogue muddies potentially clear messages and pushes the conversation into a direction that may serve no purpose. Saying too much screws you over (unless you are very good at making the awkward come off as charming- an art that depends on contrast and tolerance to the most subtle degree.)
In order not to say too much, we must focus on the core of our notions. You do not weed a garden by the leaves, rather you take them from the roots. By focusing on those roots, we gain awareness of what we actually want to convey and (hopefully) why. We find the reason for opening our mouths and sending forth minute vibrations in hopes of fulfilling our internal motives.
By gaining clarity, we bring ourselves into a position where we may easily discard that which is not necessary in order to obtain our goals. In that position, we are gain much more access to our intuition- we tap into that flow that allows conversation to bring about understanding, connection, and pleasure.
More is less. Speak from the heart (of the subject, at least.)