I USED to say ‘you know’ when I was young. Didn’t even realize it...
One day, a family friend (Of the parents family - I had never met him before but he was the son of a trusted friend of my mothers’ from NYC and five years older) listend to me say ‘you know’ one too many times... he got in my face and said: “ I KNOW!”
After he said it five times I realized what I — did not realize — I was saying.
This is similar to the method used by Toastmasters, the amateur speech groups across the nation.
When a speaker says "uh", the entire group says "uh".
When a speaker says "ya know", the entire group says "ya know".
And so forth. It does help people improve their speaking skills, and they know they need the improvement, so it is not so embarrassing in the amateur group -- not so much as it would be during a presentation to the executive committee.
Barry Soetoro refined that to "yo".