What annoys me is when I am perfectly up front about something in the beginning, such as "I like to have time to myself and I can't stand clingy guys". And the guy is like "oh that's perfect because I can't stand clingy people and need time to myself too."
Then the next thing you know he is complaining because I want to spend an evening curled up with a good book - alone - instead of hanging on him 24/7.
me: "I *told* you I like my 'me time'
him: Well I didn't think you really meant it!