Yeah! I am glad to hear this. I too am at the point where they are no longer able to detect any cancer, at least right now (Yeah again!).
Very true. Some cancers can be quite slow. Mostly this is good, but can mean that it can take a very long time to know whether it is gone or not. In the mean time, we live our lives (and hope to see our kids do well).
This can vary quite a bit.
Regardless I am glad to hear that your father is recovering. I think that your determination will serve you well in life. Best wishes.