I think that's quite common for stutterers, yeah. But it's probably got more to do with that knowledge you mention (and dismiss) than you think. It's just that the knowledge takes the shape of "traumatization" more than anything, I think. It's not that we "foresee" anything, really. We just feel the "scars" of many past encounters with these sounds (depending on how it's been going within a certain period, or periods, or however that might work). And this tends to work against us, because we get afraid of the sounds in advance. This is not somehow our own fault, of course. It's based on what's been happening so far, not just an invention of our own. And it's not like we have any detailed accounts, we just have this "scarring". Mind you, it seems to be not always the case that we feel like this. So there's gotta be more to it. But we already know that there are a lot of factors involved in stuttering, so that's nothing new, really. We may be susceptible to overall "scarring" with regards to any of these factors, such that we can get nervous for many reasons. Best thing we can do is probably to try to get familiar with our own stutter. When things go alright, we have to make note of it. Just so we don't think it's impossible. We probably especially have to pay attention when we succeed with cases we were expecting to go wrong. Dunno if this makes sense to you. :)