OP. “How does one learn so much?”…
First of course you have to be really drawn to music. Assuming that… then you have to be drawn to really complex problems. Over my lifetime I realized… I am ok at book learning… but I really like and am really good at multidimensional problems… I really like sideways thinking… considering many different aspects of a problem at the same time. So, you must navigate marketing BS, technical specs that do not reflect actual sound quality, figuring out what aspects of sound you like, technically grasping really fuzzy aspects of sound, assessing sound… research… etc. I am sure you could pursue high end audio for a couple of lifetimes. So, it holds the interest in some people over fifty years… like me. It is constantly rewarding.
Not surprising, one of my real joys of my career has been leading organizations to chose and implement global software. Same deal, highly ambiguous multidisciplinary problems. It also allowed me to afford increasingly high quality audio equipment.
