Samuel L. Jackson used to stutter, and what I read somewhere is that he overcame it by walking around saying "Motherfucker". EDIT: Source: [https://www.cinemablend.com/pop/Samuel-L-Jackson-Uses-Swearing-Fight-Off-His-Stutter-56517.html](https://www.cinemablend.com/pop/Samuel-L-Jackson-Uses-Swearing-Fight-Off-His-Stutter-56517.html)