Simple, really... yet oh so complicated. I think I've finally got it figured out myself, but it was a learning process. It all comes down to confidence. You see..
Years ago, in my pre-teen to early teens, I used to hate insults. They'd crush my confidence, and I'd never have a response to someone who insulted me. Hell, I might even still consider them a friend, wishing that they'd like me! What was my problem? I had low confidence to begin with and I had already attributed the insulter with a higher value than I did myself. I admired the person because I percieved that they had what I didn't know how to get (i.e. success with girls, athletic skills, popularity) and I had no confidence in my abilities to achieve those things nor did I value the skills that I did have. If someone called me a loser, I'd just figure they were right and go pout. Or maybe I'd get pissed, but try to hide it, only to vent to my friends later. Either way, I was completely insecure and passive.
As I grew, I learned to be comfortable with myself. I no longer idolized others for their abilities, instead placing value on my positive attributes - such as intelligence, having many good friends, etc. I also around that time discovered some of my talents that I didn't know I had. I started playing guitar, and was a complete natural. I also seemed to excel at snowboarding - I was fully trained as an instructor by the time I was 14 (but couldn't teach until I was 16 legally). I started to really be confident in my abilities in many areas in life, and started making even more friends and even finding success with some girls. I still had no idea what I was doing with women, although I had a pretty good idea, I still considered many to be "out of my league."
And then I found this website, and I felt like I finally found the missing pieces to my puzzlement over girls. I went out shortly after reading some simple advice (not even from this site, just from a friend of mine who is great with women) that said "Just treat the hot ones the same as the ugly ones, like you don't want them. Any guy can get a hot girl if he knows what he's doing." Not two weeks later, I found myself with my first 9 - and she was the one chasing me. I also went out and got myself 15 phone numbers in one night, as well as two kisses (well three counting a girl I saw 3 months later who recognized me from that night and actually kissed me). All of a sudden I had confidence in lieu of my biggest insecurity: women. I sat down and thought about it, and I had achieved most my goals. I would consider myself attractive, I'm doing well in college, I'm a good athlete, I'm good with girls, and I have lots of friends.
It was like my dreams came true. I used to "wish" I was better with girls, and "wish" I was better looking. Now I know what to do with girls - and while I'm not as good as I'd like to be, still, I KNOW that I will keep improving. I also have started working out. I no longer "wish" to be attractive. I know I am for as long as I choose to be. I also study hard, and I know I will be successful with a college degree whatever job I CHOOSE, not the one I'm "lucky enough to find." Accomplishing what I didn't ever believe I could gave me the one thing that I believe is key to confidence: EMPOWERMENT
So now somebody might say "Aaron, you're a loser!" and I'll laugh, because this loser is well on his way towards being a rich scientist. Or they'll say "Aaron, you talk too much. It's annoying" and I'll laugh because they're the one annoyed, not me. I don't need people to like me. Besides, judging by the amount of friends I have, there's no way everyone thinks I'm annoying.
You see, I realized that it is within my reach to become everything that I've ever wanted to be. If I want to be rich, I need to learn how to handle money. If I need help, I can befriend successful people and ask them for advice and guidance. If I want to be hot, like a model, I need to keep lifting and watch my diet. If I want to be good with women - well, that's the easy one really. A confident, successful man with a nice body and great social skills has everything he needs to be good with women already. Hell, I might know too much...
But you see I wasn't always confident. I didn't value the skills I did have, and in failing to do so I also failed to adobt the attitudes I needed to acquire the skills I didn't have. In the end, however, I know that I have what it takes - and that's what confidence is.
Oh, but what does that novel I wrote have to do with your question? Well I couldn't really answer it without explaining WHY insults don't phase me anymore, and why I could care less about rejection. If a girl doesn't want to date me, oh well. Maybe I came on too strong, or acted weird. Or maybe my deodorant wore off and my armpits stunk, or I had garlic breath. Or maybe she's shallow, and I'm not hot enough for her. You see, it doesn't matter. She could look at me and say "No, I don't want to give you my number because you're boring and not all that good looking either" and I'll think "That's weird. I wonder why my conversation seemed so boring to her? Oh well I was having fun." As for her calling me ugly, I might think "Well Abe Lincoln was ugly. People seem to remember him alright."
And if I really think she's right, I'm not good looking enough, I'll make a note to check my workout and maybe think about getting a different haircut. That's if it bothers me - I'll nip the insecurity at the bud with an "I can fix that" attitude.
So next time you see me on the streets, go ahead and say "Hey, freak! You're such a tool you might as well kill yourself" and I might just smile and wave with a slight chuckle.
In the meantime, work on your confidence by 1) noticing the good things about yourself and learning to recognize that they are valueable and 2) recognizing what you've "always wanted" to be, and make a plan to actually be that - no matter how impossible it sounds. If you truly believe that you can handle anything, no insult or rejection can ever touch you again