This is indeed the best way to digest and understand complex concepts and ideas. I am a very quick reader (60+ books per year), and I always summarize the most impressive books to my husband and friends. Reading a lot about about quantum physics recently (Quantum Physics Made Me Do It is incredible), and raising this topic had definitely led to quite a few fruitful discussions and a deeper understanding.

Working as a librarian back in the days, me & my colleague had to familiarize ourselves (on a surface level ofc) with over 3000 books from the collection. Each of us read 3-5 books per week, and we would summarize those to each other at a weekly meeting. That was incredibly helpful, and I'm in love with the concept of book clubs since then. Looking to join one btw!