If you want to learn a non-fiction subject, university reading lists are a great place to start. It's a very different experience reading a textbook when you do

If you want to learn a non-fiction subject, university reading lists are a great place to start. It's a very different experience reading a textbook when you don't have to take an exam -- or even re-reading one that you read when you did. For me, the dry wit of the authors comes out more and you can focus on stuff that really interests you. The other nice thing about this approach is that some textbooks are commonly recommended by different universities for the same courses -- and they're more likely to be good. For some random examples, Horrowitz and Hill, the art of electronics (for electronics!); Riley Hobson and Bence: mathematical methods for the physical sciences (for vector calculus); or David Mackay's book on information theory (legally freely available online, published by CUP and contains lots of Bayesian stuff the average HN reader would probably love).