I have not looked through in detail but it seems I am doing some lessons several times in the course titled Endings Openings and a taste of the Middle. My main concern is that they are not the same and I am just failing to see the subtle differences. The trend began with lessons concerning the concept of opposition and seems to continue. Any thoughts?

Yes, some lessons in this course are presented more than once to reinforce very important concepts so that the student can master them.

Thank you very much!