Excellent question (see how much fun we're all having answering it?) My answer is a little trickier because now, six months after ret sig to remove an almost 3.5 CN tumor, I'm the me I was years ago. I didn't realize how much I had changed, and when I did realize something was different, I chalked it up to age (54 now) or my diabetes. I was moody, lethargic, short tempered, etc.
Since the surgery, I'm the old, sunny me of my youth. I always see the silver lining, my depression is gone, I'm (slowly) losing weight without even trying, my sense of humor is back (much to the occasional chagrin of my family and friends!) and I'm just enjoying life so much more that I have in years.
Are these changes because the tumor (well, one of them) is gone, or is it because I faced a near-death experience and overcame it? I don't know. But I know I would never even consider going back to the sad, depressed person I was before I was diagnosed just over a year ago, much less the crazy person I became after the diagnosis.