Sometimes it means that a lesson I've taught was so successful that I want to share it with my other classes.
Sometimes it means that my original idea didn't work the way I thought it would when I took it out for a test ride. When this happens I changed my mind means I've reworked the lesson plan and added or removed elements, adjusted something to extend the process or shorten it. When you teach the same lesson to two classes with differing class times, one with adult support and one without this is what you do. The final outcome looks similar but the process is different enough to keep both age groups engaged for the full lesson time. Even then, there are times when no matter how carefully I've crafted a lesson there are early finishers and time to fill until class time ends.