I used to be really shy, and I'm not anymore. I've taught myself to hit on girls properly and have found out that they
actually like me and that most of my first attempts were in vain due to me not being obvious enough.
Anyways, about the supposed contradiction of shyness nurturing itself from your ego: It's often true. If you're expecting too much of yourself due to a warped idea of how great you are and feel a need to shield your ego from being hurt, it's often shyness.
There's no need to protect your ego from failing. We all fail and all deserve to.
What I've personally realized (which is a dark view of things) is that
everyone in this world, including myself, does not live up to any kind of greatness. Rather, everyone is an unimportant creature of sad indifference. Shyness often results from great expectations of how you & your things should be, but in reality, the whole world is a miserable place. The trick is to celebrate it with all the other creatures of misery in this black void we call reality. I smile at it, think it hilarious, spit it in the face, and savor the small things with people that are as ungreat as myself. It's actually a lot of fun (And makes for great music.)
Spending a lot of time alone can make you be very afraid of doing wrong things. Isolation can cause you to emphasize too much on the things that you did wrong that one time. In reality, most
adult people forget about it or don't care about you enough to make a deal out of it. So there's no need to not try socializing.
And girls get hit on all the time; if they can't handle it like a proper human being (eg if you attemp kissing someone at a party and they reject you - and afterwards spend a lot of time showing you that you're dirt with vile looks or attempted mockery or

-faces) they usually have some kind of confidence issue which they feel a need to overcome by telling themselves of how much better they are than you. Again, to what I understand of this world, they forget that they're not supposed (or able) to contain any eminence at all. If you'd notice, the above behavior is very immature and highschooly; the age of insufficience and the need to confirm oneself's social standing; it's been a really nice experience for me to grow up and figure out that people were actually not that ridiculous from the twenties onwards.
Anyways, point is that all individuals experience some kind of insufficience which is what is the root for shyness to some individuals. I overcame shyness personally by realizing the insufficience was irrational, and natural. I see no people as sufficient in themselves and all people as having the same reason to be shy as you have. They just learn not to care.
Or perhaps savour the thrill of nervousity rather than fear it? I get
suuuch a good kick out of not knowing how a girl might react when I move my face towars hers. It's the best part, actually...
The world is a horrible place with miserable people and it will never change. Let's celebrate that.