Sounds like he just doesn’t want to talk about it. And I’m guessing he’s had a stutter all his life… judging from the fact that you said he used to have a mild stutter. Stutters can come and go, and get more or less severe at certain points in life. The vast majority of adults with stutters have had it since childhood. It’s very rare to get a stutter later in life. …. Although I have heard of brain tumors, heavy drug use, and MS causing stuttering later in life.