"The definition of stupidity is doing the same thing over and over again and expecting different results."
And, he wrote that before personal computers were part of everyday life!
So, if it isn't working (the lesson, the diet, the classroom management strategy, the nagging, the software, the job, the lifestyle, the healthcare system, whatever...) try something else. Doing something different could require some creative thought and possibly a great deal of courage, but it could also reap life changing results.
Picture above from the book The Key: and the Name of the Key is Willingness by Cheri Huber.