I'd imagine it could vary by person though. I don't have a stutter, but will sometimes stop mid sentence and forget how to form the rest of the words, and struggle with word retrieval a lot. It annoys me a bit when my mom tries to finish sentences since she's always wrong haha, so then it makes it harder to say what I'm actually trying to say. But when someone actually knows what I'm trying to say I do like it when they help me out so I don't remain "stuck."