Thank you for this detailed answer!
I was told that the shocking moment was not the reason, but I though it a long time. In real it started years after this moment, so there was anything other than this.
The secret is the flow, here you are 100% right!
And there are a lot of ways to come into that flow. Drumming was my way.
If you look to my videos you will never think that I was stuttering so hard :) It is gone away now.