My therapist, Nancy, had a book for me to borrow today when I went in. It was called
The Highly Sensitive Person: How to Thrive When the World Overwhelms You. It's a really good book and OH GOD does it finally help me to make some fucking SENSE of my life.
The book isn't saying that other people aren't sensative, or that the five senses of a highly sensitive person are any more acute. The image that Dr. Aron used to elborate was that machines that sort fruits by size; most people's machines sort into two or three sizes whereas a highly sensitive person (referred to as an HSP) sorts into more along the lines of ten. Things that most people can handle are simply overstimulating to HSP's, which leaves them exhausted and in need of quiet time to recharge.
One of the great things about this book is that being an HSP isn't treated like a problem to be fixed. HSP's are not somehow "wrong" because they spend a lot more time alone than the average person.
Anyway, it's a good book and I recommend it, even if you think that you fall into the HSP range, it's a fun read.