Ask HN: How do you share the stuff you find interesting while reading a book?

Many a times, it happens that after reading a killer book I want to talk to another person about specific ideas I read in that book and discuss it further to consolidate my understanding, also it acts as a great conversation topic. I however feel sometimes that not all friends want to listen to the book talk you have to say, or specific books can be talked with specific persons only. To resolve this, I would rather put the central idea as a tweet or a story somewhere to engage with like minded people. I want to know other ways people do the same