I'm right there with you -- not recovered and unsure why. (and I'm a speech pathologist with 3/4ths of a PhD in communication disorders) The scientist in me wants to know why, wants to investigate. Wants to prevent persistence. The clinician in me wants to say, there are lots of factors and we can identify globally what those are, but there's not one necessary and sufficient criteria for persistence. The stutterer in me, sometimes just wants a pill (but then sometimes I actually enjoy that I stutter).