Stress and anxiety make a stutter much worse and more visible. >this was the the time I started secondary school... The next year when I was 14 my stutter disappeared You were stressed out and nervous about starting a new school. Once you adapted, your fluency rose. You can probably trace most of your low-fluency points to stressors (as I'm sure most of us can). It doesn't always have to be something big. Stuttering once could make you think it's "returning", which stresses you out, makes the stutter worse and more apparent, so it becomes a self-fulfilling prophecy, etc.