But new studies at Princeton suggest that disfluent lessons are actually more effective forms of delivery for "long-term learning and retention". The simple reason is probably that in order to learn, the brain must actively engage (i.e., work) to make the necessary connections in order to come to a useful understanding of the presented material. If everything's nicely handed over on a silver platter there's little work for the student's brain to do. Usually, the one who learns most from such a lesson is the teacher who's connected all the dots already then presented the finished picture. Where's the fun in that?
So, maybe we should stop beating ourselves up over lessons that didn't go according to plan. The harder the kids have to work for meaning, the better they'll appreciate it. Hopefully, they'll remember you and come visit you in your retirement home when that "ah-ha!" moment finally arrives.