Right on the mark. This is an excellent explanation of what I alluded to in my response to your preceding post: chess is not learned by passively absorbing material. You have to work at understanding the games or positions you look at. It's hard work, requiring concentration and dedication.
I wish I had understood that years ago instead of wasting so much study time.
1. TIME
2. REPETITION
3. YOUR ACTIVENESS
4. LEVEL OF DIFFICULTY
5. MEMORISING
6. FREE/PAID
7. EFFECTIVENESS
CONCLUSION