Donk: I have a thought that is a little different, but similar. Also at the risk of sounding arrogant or self-focused, but this is a forum for honest discussion about our thoughts, right? My thought is that sex with me, whether good or bad, long term or one night stand, will always wind up being a memorable experience for the girl.
Unless the girl is a size queen who makes a habit of seeking out and bedding well-hung man, odds are that my 11" penis is the biggest she has ever had or probably will ever have. Even if I'm not performing at my best, I know that my penis will stand out in her mind as something unique compared to all the other averag-sized penises she has seen. I often hear guys comment that they worry about whether a girl is going to mentally compare their size to past lovers and how they would measure up. Again not to be arrogant, but it is somehow reassuring to be "that horsehung guy" instead of the guys wondering how they measure up against "that guy".