[hannasanarion]

I have this only for concepts on radically different topics.

If it's something about history, I probably learned it from Revolutions, because I don't read a lot of history otherwise.

If it's about cryptography, I probably learned it from The Code Book, because I don't read a lot about cryptography otherwise.

If it's about language features in Python, heck if I know where I got it from, I watch, read, hear about, and find new stuff about python all the time, it's my job.