Books, not just reading but long form text. If someone doesn’t want listen, then they won’t even if they pretend otherwise.

So if a talented author puts out a message, the reader has to continually choosing to read, intake and process what is being communicated. It’s easy to tune out of conversation, videos or lectures without realizing it. But if you make it to the end of the page and don’t know what just happened, it’s entirely at your discretion to go back and reprocess. Infinitely repeatable while requiring constant buy-in without the concept of just waiting out the duration while thinking of other things. To my mind, if you want to understand a complex idea than books are easily the best method.