I really dislike going out for lunch with colleagues because I am very aware of what I'm saying and that I do seem to "hold court" quite a lot.
I often say to people, "oh just tell me to shut up, I do hate the sound of my own voice"
BUT when we go for lunch, we sit down, order drinks and everyone just seems to sit quietly waiting for someone else to speak - now one thing I hate more than the sound of my own voice is weird uncomfortable silences when in company, so unfortunately I tend to overcompensate by talking shite and revealing things about me that I shouldn't - It's just like a panic takes over, and in my head I hear "keep talking, keep talking, keep talking"
I am always thinking 'why won't someone else speak' but they very rarely do, even when asked 'have you ever done anything like that' or 'what do you think'
Of course that's only with work colleagues - and realistically what do we have in common with colleagues apart from the fact that we work together hey? With friends I'm an absolute gem 
Now I'm leaving this post as I realise that I have referred to myself (as I or I'm) about 14 times yawn
See, I've gone and spoke about myself so much that I actually forget what the OP was saying...
Ah, conversation dominators, YANBU, but is there anyway that the people you refer to may think the same as me?