I read this book in the late 90s. It was borrowed from the local library and was quite old then.
It was about a man who had lived in a lunar colony which had pioneered a way of life that allowed the people to be connected. They had ports surgically implanted and could share info and talk to each other remotely and 24/7. It was frowned upon by the Earth dwellers who thought it was dangerous.
He moved back to Earth and had to disconnect. Most of the book is about his rehab/recovery on Earth and his discovering more about the lunar colony's connectedness.
I was sure the author was Arthur C. Clarke but I just can't find it.