The whole process from the casting to the shooting is enjoyable to me.
Knowing I am doing something that the vast majority of folks do not do.
Knowing I am able to load for & shoot every different caliber/gauge I own(15), with the only exception of .22 S/L/LR.
Knowing the satisfaction of teaching others how to do it, & seeing my sons & grandboys take an interest to carry on, is enjoyable as well...
I'd bet I could go on with things that make it enjoyable.
I think that of all the things I enjoy thru-out the whole process, the part I like best is the load development & testing.
Seeing the results of what was done thru out the whole process come out and reach a goal & know that it was my own work that reached that goal, and seeing it better than factory made ammo, is the "icing on the cake".