The reason he's quiet and creepy is because he never developed any social skills, and doesn't have the gumption to start.
The reason he unloaded his affection on you is probably because you are nice. Iv met nice girls and thought about how great it would be to be with them. I have no doubt in my mind that I could make a girl happy. The difference is, I either keep my mouth shut and keep my intentions to myself (im good at hiding what Im thinking), or I open up to the girl gradually and gauge whether or not she is interested (Im good at reading people.) I would never want to be with someone who doesn't want to be with me. Nothing turns me off more than apathy.
I know how to be disarming, and I have my funny or clever moments. The reason most guys suck at that, is the same reason most people suck at poker. They don't even know what skills they need to be developing. They think telling a girl she's beautiful and offering her a drink is something that doesn't happen to mediocre girls 100 times a day. They try to force situations, when they should be picking their battles.
I am by no means a player, or any kind of raving success story when it comes to dating. If anything Im too passive. What I can say though, is that I don't creep girls out, and I am never ham fisted in anything I do. I am, in fact, so disarming, that girls who are in a relationship have told me, or my friends that they would date me if they were single. I guess when the pressure's off, I really shine.
The funny thing is that these guys who think they would be so great for a girl would bring nothing to the table. They are the kind of guys who would never take you out, never think of anything interesting to do, never have anything interesting to talk about, and sex with them would be 30 seconds of awkwardness. When you threaten to leave them, they just cry and threaten to hurt themselves. I hate to be a jerk, but these guys don't deserve a girl. They just need to be ejected from the playing field.