My wife had a knee replacement a few months ago. She had 3 issues that were causing serious pain. Now the pain is gone and she says it was the best thing she ever did. She has her full range of motion back. During physical therapy, the trainers she worked with said people say that all the time.
Don't get me wrong. She had to work hard, and rehab wasn't easy. There were times she didn't think she'd get better. But it did.
Just my two cents.