As a teacher I like to recycle lessons, particularly what used to be called Topic Work and in now called IDL (Interdisciplinary learning, eg: The Home Front in WW11 or The Journey of Food). In years gone by I would repeat a topic for three years in a row. I always thought that the second year of using and adapting the same material was the best, the third my enthusiasm was probably flagging a little and it was time to move on.
Currently, working in a very small school, I teach a class with 4 year groups. This stops me recycling in this way, I’ve got to plan everything afresh each year. The coverage needed for the Scottish curriculum makes this a bit harder now too. At my age a 4 year cycle before I can try again with something that has gone well seems like a long time.