Aristotle understood the soul as the function of a certain material. While he saw certain aspects of it as immortal, overall It's wrong to think of your soul as being separate from the body. He thought that giving shape to it, as in your functionality could even take an entire lifetime.
I think joy is really linked to people's own image, that's why people feel fulfilled when they do a good job, or get people to respect them. In the nihilistic societies we live in, constantly under the influence of the ruling groups, I think one way people can find peace is by becoming really good at something. I've sure have found peace in resisting the system and fight for a better future for my nation. I think I can only feel joy by fighting somehow anymore.