I've been in and out of this pursuit since around 1970. There have been periods of my life where I didn't even have a system set up, though I stored the gear and LPs. I don't subscribe to, or read, the audio magazines any more, though there were periods early on when I was an avid reader. And there were times when I was consumed by the hobby in the process of improving a system, doing big home theater systems in my homes using projection (starting in the early '90s).
My current main system started pretty much from scratch in around 2006-7 and the core of that system remains in place. I set up a vintage system based around several components I owned since the early to mid '70s.
Much of my attention in the last decade plus has been focused on jazz from the early '70s--more the spiritual or astral stuff and soul jazz rather than "straight ahead" material, though I'm a fan of Art Pepper.
I'd say it's normal for interest to wax and wane. Most of us are gear heads and get caught up in the sonics for their own sake--to me that's a trap and the analytic part of listening for improvements (some changes are just "different," not necessarily "better") detracts from taking in the music for its own sake. That said, I have musical preferences that change over time, and it's nice when the sonics of a recording/pressing bring out the best in a recorded performance.