What are the big ideas and streams of thinking from before the turn of the millennium that have shaped our field and may still be relevant today? For once, we did some homework to review some of the theories from before the year 2000 that we think everyone should know about. So whether you are studying AI or algorithmic aversion, digital transformation or digital innovation, you have no business continuing your research without knowing these gems from the past. As usual, the references to readings we mention are listed on .