Yep, I get that way too in meetings. Just lack the confidence to speak up for fear of blocking, and then everyone just looks at you whilst you struggle to get it out. I tend to stay quiet as much as I can unless I'm asked a question directly in meetings. It sucks because most of the time I have things to contribute but I fear blocking so much :( The first day of a training course is the worse, when the instructor goes around the room and you have to introduce yourself, where you work, what you do, what you expect from the course etc.. I try to avoid the first 30-60 minutes of a course for that very reason.