You may not hear it yet, but you soon will. You may already be doing it yourself. I was. And now, I realize, I do it all the time: I use "no" at the start of a sentence to mean "yes."
It turns out that English once had more options for saying No - no and nea. "No" was a negative response to a positive question, and "nea" was used in response to a question that was phrased in the negative. The demise of "nea" left us with a problem:
Q: Don't you like the song "Operating" by Hunter Hunted?
Does this mean I hate the song, or love it?
Schulz theorizes that answering a question in the affirmative by saying "No, definitely" might be a resurrection of the grammatically extinct "nea." But we're extending its usage beyond the traditional. My interpretation is that we're using it to preemptively dismiss all other possible answers.
Q: Isn't "Summer People" by Kelly Link one of the best stories you've read in a long time?
A: Yeah, no, it's just amazing.
Witness the real-time transformation of language.