Have you read the book The Highly Sensitive Person, by Elaine Aron? It was recently recommended to me, and while it wasn't necessarily hugely life-transforming, it did speak to my nature in a way that Susan Cain's Quiet never did. I find that "introvert" describes me much less accurately than "HSP" does. I gained a great amount of confidence, in retrospect, in my own childhood and adolescence, by looking at it through the lens of "OK, being highly sensitive as a kid and teen WASN'T a bad thing, and didn't necessarily take away from the validity of my experiences - in fact, it probably made them more accurate." I've been able to take a lot more ownership of my perceptions, thoughts, feelings, and experiences of late, and I have to say, feeling not-invisible for the first time in my life feels AWESOME. Even if my family and in-laws and everyone who's known me for a long time is wondering what the heck got into me.

(Also, re. your point about Sesame Street, Fraggle Rock made me sick to my stomach as a kid, and sometimes Sesame Street made me queasy too, and to this day I can't see a Fraggle without my stomach lurching in remembrance.)