I have a "highly sensitive child"- now what?

my "HSC" boy as a toddler.

I thought I knew a bit about parenting. After all, I had spent ten years working closely with parents as part of my day job, not to mention the fact that I was already, in fact, the mother to one little boy. I had "planned" my second pregnancy and we were blessed to welcome our second little boy into the world in July 2006. I had a healthy and uneventful pregnancy, followed by a quick, uncomplicated birth. Bliss, right? Well, let me tell you that from the moment he was born (and even perhaps from before he was born), I knew there was something "different" about my little one. He literally did not stop crying from the moment of birth until he fell asleep briefly five hours later! After which he continued to cry and then sleep in short bursts for months on end. This child was irritable, demanding, inconsolable and above all exhausting! But confusingly he could be so engaging and adorable too and developmentally, he always met his milestones early.
Eventually a number of medical issues were diagnosed and treated which was helpful but my husband and I found that just as some issues would resolve, others would develop. In general, our little one seemed to find everything "more" or "extra" than other people and he would simply become totally overwhelmed easily.
As the years have gone by and we have gotten to know our child better, we realize that our little one could best be described as being a "highly sensitive child". This is a term explained in Elaine N. Aron's book called "The Highly Sensitive Child" and reading it was literally like a lock turning into place in my head. Essentially the highly sensitive individual is someone who "notices" more in the environment than others and they process and reflect on things more deeply. Because of this extra "noticing" they can be easily overwhelmed and may seem shy, cautious and controlling. The plus side is that they can be sensitive, empathetic, creative, careful and conscientious individuals.

The descriptors in this book fit our son so perfectly which has served to really help us to understand and support him as he develops. I also think this book helped us as his parents to be able to re-frame our frustrations and anxieties into positives and to begin to celebrate some of the things that make our son so unique.
Has anyone else found this description fitting for their child?