As it turned out, I had plenty of material. In fact, I didn't even get to most of it. There were things that I would have liked to have said more eloquently, and points that I had definitely wanted to mention but afterward realized I hadn't talked about at all.
I have tried to have an attitude of allowing the Spirit to guide me through my talks and lessons. And I really do trust that Spirit led me to those points which were most important for me to share.
So while I prepared a lot more than I ended up needing, that's not what was important. It was a lesson, I suppose, in allowing the Spirit to be the teacher, rather than myself. It was a lesson in humility: a matter of realizing that no matter how well I think I can say something, my impressive choice of words will not convert someone to the Truth.
Only the Spirit can do that.