“I spent a long time waiting to feel joyful, instead of actually learning how to be joyful.”
That's the whole idea behind Joy. The only two things anyone ever fully controls are their actions and their attitude — everything else is circumstance. Joy doesn't treat that as a nice idea to meditate on. It treats it as a skill: something built through daily, deliberate practice, the same way you'd build any other skill worth having.
Not a content library to browse. A curriculum to complete.