Yes, it can be joy - sometimes. I find it joyful if it comes from me rather than a publisher or editor. I suddenly thought of changes (for the better) that I could make to a story I first wrote many years ago, back in the 1980s. It's been through quite a few changes since then but this week I put it through a total transformation and then some re-writes. It actually gave me a little thrill to read it over. I'll leave it to ripen a bit more before I re-read and then send it somewhere.
I've also taken a deep breath, decided not to panic, and just work on different stories as the inspiration hits me. For, lo and behold, I read a few scenes from two of the stories I have not looked at for quite some time, and I thought, 'How brilliant? Who could possibly have written such gripping prose? ... Why, bless my soul, 'tis I!'