That Ubiquitous "You Know"

Here's Caroline Kennedy in an interview:

..."I'm really coming into this as somebody who isn't, you know, part of the system, who obviously, you know, stands for the values of, you know, the Democratic Party," Kennedy told the Daily News Saturday during a wide-ranging interview.

"I know how important it is to, you know, to be my own person. And, you know, and that would be obviously true with my relationship with the mayor."

...Displaying her notorious shyness during the 30-minute chat, the mother of three, author and public education advocate was pleasant, but spoke softly and rarely made eye contact. Her speech was often punctuated with extra "you knows" and "ums."

..."Andrew is, you know, highly qualified for this job," she said. "He's doing a, you know, a great job as attorney general, and we've spoken throughout this process."

..."You know, I think, you know, we're sort of, uh, sharing some of this experience. And um, as I've said, he was a friend, a family member, and um so, and uh obviously, he's, you know, he's also had an impressive career in public office."

..."It's really, you know, it's not about just the Kennedy name," she said. "It's about my own work and what I've done with those values."

If "I know", why does she have to tell me?