How and why is confidence sexy?

Confidence doesn't mean being bombastic or bullying. It also doesn't mean never asking for someone's opinion or advice, or saying that you don't know something, changing your mind or saying that you're sorry if you mean it. It means being comfortable in your own skin and true to your own values. It's somewhere between annoying to infuriating to spend time with anyone whose opinions change like a weathervane just because they want to be liked, doesn't get anything done because they're too busy wringing their hands about what people will say, and don't even know what they, themselves like or think anymore. Or worse yet, constantly apologizing about stuff that they're not actually sorry about but are too much of a coward to be true to themselves and let the chips fall as they may.

Confidence is learning that not everybody has to like you and not liking you doesn't make them an automatic enemy. Confidence is liking who you are. That's genuinely attractive.