What’s the point, y’ know, of communicating?

I’m bedeviled by “y’ know.” Everywhere where I go I hear “y’ know.” From a literal standpoint, I don’t know, and I must assume I will be told, that is, what I need to know. Out of politeness, I don’t say “No, I don’t know,” since that would be humiliating and embarrassing to others. But I often think it.
Now “y’ know” has a perfectly reasonable place in speech as a both a question and affirmation. When used as a question, “y’ know?” works fine. I can nod my head in assent or indicate that I need more information. Similarly, “y’ know” used as an affirmation is also acceptable, as in “Barack Obama, is the President, y’ know.” My bedevilment arises from “y’ know” used to fill a pause in speech, as in “I was, y’ know, talking to my, y’ know, mother and she kept, y’ know, interrupting.” This is a direct quote.
I keep wondering how “y’ know” emerged as such a commonplace and frequent moment in speech. There are people who constantly use “y’ know” several times in a spoken sentence, and on such occasions I find myself losing track of the words in between. Like some sort of religious incantation, “y’ know” becomes like “praise God” but of course, it is not.
Speech is too often a hurried affair. In an age of increasing speed, speech has also quickened. Words are said in passing, with little time for consideration. Glibness and quickness are viewed as positive talents in an age when everyone is in a hurry. We bestow fame and adulation upon those who minds and mouths work fast in perfect coordination, for example, Robin Williams. His verbal calisthenics hold our rapt attention as we surrender to the unbroken flawless flow of his expression; you’ll not find an errant “y’ know” in his routines.
For those whose minds do not work quickly “y’ know” provides a gap or space providing time for thoughts to catch up with the mouth and pace of conversation. But for some, “y’ know” also becomes a speech habit, a repeated response to the rush of thoughts and ideas still forming, serving as a place-holder while clarity sweeps away confusion. There is also a defensive element of filling space that could be occupied by others, as if in the rush of words every spot not filled will be usurped by interruption. Given our increasingly speedy minds, fearing interruption is not unwarranted. For some people “um” plays the same role as “y’ know”, and is like saying, “hmm, give me some time to think.”
The problem is that “y’ know” and “um” break the continuity of conversation and are distracting; a better solution to needing time to think and speak clearly is to slow down. Slowing down, of course, runs counter to most everything today; we live in an age of speeding up. “Faster” has become a sales pitch, glossed with inferences of more power, success and increased fortune. But faster is not necessarily better, and when it comes to speech, thoughtful works better even if it’s slower. This means both speaker and listener must be more patient.
The point of communication is to be understood, not just heard, y’ know.