Today, he came to me and said, "mommy poo poo" so, we headed upstairs and he let me know he wanted to use the big potty. So, we gave it a try. About 15 seconds later, he decided he was done, but had done nothing. Back downstairs to play.
About 10 minutes later, same thing. This time, we had success! He poo poo'd on the big potty and even waved bye as he flushed it. Just like the book we read the night before.
I was blown away! I hope it isn't a one-time thing.