1. Human biases: Every mental model is built upon some human bias.
2. How incentives work: Understanding the motivation behind why people do what they do.
3. Mental thought construction: Understanding how the brain gathers, processes and stores information.
4. Biology: How we've evolved (and haven't) from stone age times and how that still influences us today.
This is by no means exhaustive but are just some of the topics I've found most useful. That said, here are the best resources I've found:
- The Art Of Thinking Clearly by Rolf Dobelli: Taught me about human biases. Reads like a directory of most biases.
- Influence by Robert Cialdini: Taught me about incentives and a whole lot more.
- Metaphors We Live By by George Lakoff: Taught me about mental thought construction.
- Poor Charlie's Almanack by Charles Munger: Taught me about many things but most importantly good decision making.
- Sapiens by Yuval Harari and his course https://www.youtube.com/playlist?list=PLE-kxvSEhkzDEmLQx3RE0...: Taught me about how we've evolved as humans and how we haven't.
- Thinking Fast and Slow by Daniel Kahneman: Taught me more about human biases.
- Predictably Irrational by Dan Ariely: Taught me more about how and why we make decisions and what good decisions are.
The thing I've really started to notice is it's not enough to know or read about mental models, you have to ruthlessly apply them. This is tough when even knowing about your biases doesn't stop you from still being affected by them.