I, too, think the emotions are a result of relief at having survived the ordeal and the effects of the anesthetic that do take a long time to pass through the body. I think another important aspect is the humbling experience of receiving the good thoughts, prayers, and kindnesses of those with whom we interact each day. We too infrequently take the time to let them know how much they mean to us. And, for that matter, we often don't realize how much we mean to them.
I remained pretty stoic and upbeat prior to the surgery because I had to get things ready for a substitute teacher and I did not have much time to give the surgery a lot of thought. Even immediately afterwards I was upbeat and excited that it was behind me. But when a friend from school called to see how I was doing in the hospital and I heard the concern in his voice I unexpectedly cried as soon as I hung up. Then a few days later after a long 3.5 hour ride home from the hospital during which I was not very comfortable, I walked into the house and burst into tears when I saw that our neighbors had left flowers and had made a pot of corn chowder for us to enjoy.
The support from this board, from friends, and from family is so very important. As I have said before on other threads, it is such a comfort to know that whatever we are experiencing there are others who have been there.