Yes there's actually an explanation to why this happens. Humans put value on certain words or phrases when we say them based on their importance.Your name is a valuable word because there is no alternative to it. You don't have another name, you have one. This is why names, titles, and reading are often a lot harder for stutterers because we can't change the words. Even punchlines to jokes are tough, because we put that subconscious value on the words because they are important to the joke and we can't get them wrong. Because anxiety (no matter how subtle) easily causes stuttering, that subconscious importance we place on certain words make us anxious, causing the stutter. When you blurt out a word or sentence, you didn't give your brain time to give the words any value or importance, your voice just begins speaking. My stutter, and most others, are psychophysioligical, so our brain does the stuttering. One of my solutions to this at least when reading, is to keep my eyes on the words ahead of what I'm actually saying. The price of this is sounding a bit monotonous when reading, but it works for me pretty often unless I psych myself out and become too aware of what I'm doing. Hope this all is informative!