For me the real capability unlock from The Design of Everyday Things was that it made me start noticing and thinking deliberately about design decisions, which pushed me to begin evaluating everything through that lens. In general it comes down to looking at something and asking "what is good / effective and what is bad / annoying about this". If you keep doing that enough you develop your own taste and a greater appreciation of the world. Donald Norman isn't handing you a map, he's teaching you how to build your own.