To truly enjoy this hobby, I need to learn electronics. Any book recs?

Bruce Rozenblit's Tubes and Circuits.

Bruce sells /  designs the Transcendence OTL amplifier kits.

I highly recommend Sound Improvement Secrets for Audiophiles. Sounds cheesy but the author, Igor S Popovich, is a highly accomplished amplifier designer. He goes into quite a bit of electrical theory. He even gives plans for cheap DIY cables that he claims outperform the big name fancy ones. 

OP, do you harbor aspirations of designing and/or modifying audio gear? If not, perhaps a solid understanding of acoustics and psychoacoustics would be more beneficial than tackling the electrical engineering, at least from an audio hobbyist or consumer perspective. WRT this, I'd recommend the seminal work by Floyd Toole, Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms , now in its 3rd Edition.

Forget about books aimed at audiophiles, like the one by Robert Harley; that’s not technical information, it’s hi-fi consumer advice.

I agree!

Mike

@rumblestrip I think part of the enjoyment is parsing the impact of different electronics and for me it is fun to understand how the different pieces work together. 

I don't want to be an engineer, but maybe I'll want to do own maintenance etc.

Thanks everyone for the great ideas!