Given a woman willing to be sexual with them, the vast majority of men are too grateful to think she looks stupid. Particularly as most of them will have their own insecurities around size / hair / muscles / fat / face / whatever.
Learn to like what you have because whatever your body looks like, it will be the ideal for someone. Some people like slim partners, some like fatter ones, most don't care. The same principle applies to breast size and everything else.
Confidence (as opposed to arrogance) is a huge part of being 'good'. It can be faked until it's real, and doesn't have to mean you know what you want all the time. Confident people can try new things, and they can say no to things.