I race motorcycles. I don't get joy out of it, I get satisfaction and a feeling of achievement. I get a feeling of ultimate focus for 15 minutes. Nothing compares to it. I can't imagine processing the experience as an emotion, that would require taking focus away from the knife edge of going fast but not fast enough to crash. My good friend races with me and he says it's the most fun thing ever, he's grinning in his helmet. We are doing the same thing, we are getting something positive from it, but we have completely different ways we experience it.
I think you and the person you're replying to may just be defining "enjoy" differently. To me, enjoying something just means you like doing it for some reason or another, not necessarily that you're on cloud nine throughout.
I wouldn't say I'm on cloud nine. But if I'm out for a ride, and things are working like the should, no leg stiffness, balance isn't off... It really does make me happy enough to smile. And that in turn makes my effort feel lightened. It is so much more enjoyable than the approach I took when I was in my 20's, which was more of the no pain/no gain variety.
I can absolutely get euphoria while pushing myself to the limit (I don't bike or wear Lycra, though.) I don't know if I have the free energy to smile in those moments...