I know. I've been to the best speech doctors, I have read the best books on stuttering, I have been practicing its guidelines to control/manage my stutter... The books, the authors, the doctors and psychologists, and everyone else told me the same thing : no one knows. Just deal with it.  But one day I was fed up with my stammering and how it affected my social life despite my all efforts. I decided to try to understand why I did it. I asked myself "I had a period in childhood where I did not stammer, so why did I start stammering?".  I also struggled with severe anxiety. All these problems started gradually around the time I entered high school. I wanted to understand why. So I 'investigated'. I read many psychology books until I came across my best:" lost connections" by Johann Hari. And with insight from other recommendable books as well, and from my own personal experience, I realized they were related to stuttering.  There's still so much I have left out. I am trying not to write a lot😅. The details are a lot, and complicated. It's not something easy and quick to fix just by yourself. To put it plainly, loneliness > lack of a sense of connection with the people around you > stammering.