I'd say it's just genetics my friend, my Mom has/had a stutter my sister as well they both learned to control it very well to where it's almost unnoticeable me on the other hand is much different lol I try not to think about it, I just stutter when I talk my family says they don't really notice it they just know that's how I talk. The worst I'd say I do is long blocks those really suck lol but I force through and get out the word