It's not about forgetting things. Stuttering doesn't just affect fluency and it has many ways of presenting itself. When I have a sentence in my head, I can often feel a few words ahead if I'll even be able to produce those sounds; if not, I have to find a workaround. That's the biggest reason why stuttering causes awkward or nonsensical sentence structure. When there is no workaround, however, you have no choice but to "forget". Another very common speech impediment that often comes along with stuttering is the forgetting of words in the spur of the moment. Your brain will just drop it's knowledge of the simplest of things, for a brief second; causing you have to explain out loud you've forgotten what the word for a doorknob is, or something. I don't experience this as much, but my partner does. It's just the general lack of understanding how speech impediments are invisible that bugs me; I see a man stuttering, yet everyone else is pointing and laughing. If they point and laugh at him, that means everyone's pointing and laughing at me, too. I'm sick of it. These fuckers don't have a clue how much they're taking speaking for granted.