^^^^
Yeah, it sucked. Scared the crap out of me. I've had guys grab me since (most recently, the next door neighbor - that was an even worse situation, because I could not physically fight back for various reasons and had to get out of there
without kicking him and running).
I don't know if it's confidence so much as righteous anger, though.
I'm not suggesting you put yourself into a situation where you could get hurt due to your response to such behavior, or anything - go with your gut. But if someone is seriously bothering you and there are other people around, like your bus stop situation, you can probably get a firm "Leave me alone" out there and have it be effective.
I don't know why I get creepers bothering me as much as I do - I don't exactly look like I'm in the mood for ANYONE's crap, and I'm not what you'd call conventionally attractive. But it happens and happens. People suck. So when they suck in your direction, let them know.