It was never determined why I talk. I saw an Ear, Nose & Throat Specialist for a different problem soon after I started making sounds. He went ahead and scoped me, stuck a camera down my nose all the way to my voicebox, to answer the Speech Therapist's questions. His answer, "There's no reason she shouldn't [talk]."
I finally figured it out. I read this http://www.usatoday.com/news/health/2006-07-03-brain-rewired_x.htm again and it occurred to me. I don't know how many times I've read it before. The first sentence says it, "Doctors have their first proof that a man who was barely conscious for nearly 20 years regained speech and movement because his brain spontaneously rewired itself."
I "regained" speech and movement, too. Rather than "miracle", it is "rewired." A reason. That's all that I needed.