I used to think the same, that blocking was the automatic behavior, but when I tried to “unblock” and realized I could, and that beneath there is a repetitive stutter! I don’t know how to explain how to do it, but you might want to try this when you’re with someone you trust. Now, if I could just decide not to stutter and speak fluently, that’d be awesome… which takes me to OP: I hate when people who know I stutter offer suggestions such as: “just relax and pretend you’re talking to yourself and not in front of a group”. Really! Wow, thank you—problem solved, I guess!