Here's my perspective, as a guy who was repulsive then attractive.
When I was in high school I had a serious acne problem. I was repulsive right at the time when hormones demanded action and all my friends were dating. It was hell.
Then senior year it all magically went away and I ugly ducklinged into a good looking guy. As my self-esteem improved I became very fashion-conscious as well, developing a sense of style commiserate with my personality, i.e. I became attractive just as I found myself. Girls liked both, a lot. The halls went from an icy hell to my friends' cheerleader ex-girlfriends suddenly talking to me with this warmth in their tone. I had no idea how to deal with it.
Someone above said being attractive means you don't have to make the first move. This is fairly true. In college all I did was talk to girls without subtext or anything, just talked, smiled, was nice and that's it. I would never make the first move because inside I was still that acne-ridden kid who couldn't believe these hot girls were into me. So I just acted nice and left them alone. They would then throw themselves at me after a couple beers at parties or, on a couple occasions, would show up at dorm room at 3am. This is how I got 90% of the tail I nailed in college.
Now that I've crested 40, I'm still a pretty attractive guy who enjoys the gym, so has remained in great shape. I get a lot of attention. It's a weird time. Women my age will aggressively ogle me in a creepy way and go out of their way to be super helpful, all with this desperate subtext that screams "F@#K ME!" Young college-aged women will smile a lot, be warm and chatty, but not aggressively so, and many times I think not even conscious of it.
Here's the bad thing though: you grow addicted to the sexual attention. When I don't get anything for awhile, I begin to really miss it even though I'm a very happily married guy who would never cheat. Part of my self-confidence has grown addicted to women's attention, even though I know it's superficial and silly. When I don't get a bite for a few days it feels like the world has gone dark. I sometimes envy those old guys at the gym who just don't give a f#$k anymore. They're free in a way I can't even imagine. Is this what it's like being unattractive? I have no idea. But I know when age does finally catch up to me (and it's happening soon) I will go through a period of painful withdrawal until, hopefully, I just accept it and relish the freedom.