I started with radios (I accumulated all sorts of things some accidentally some as passing fancies) as my first serious, continuous, lasting hobby and still like to collect and restore radios. Yeah, some do bore me....How many AA5s can you restore till you start to be able to smash a few and build a new one from the remains on memory of the schematic/start sleep-restoring them.
But for every cookie cutter AA5 there is an AA5 with a cool enough cabinet to merit doing the trained-monkey-ready restore or a non-AA5 with some clever or unorthodox circuit that really feeds my inner tube-gear-nerd....Case in point I just restored a Silvertone model 1954 tombstone that uses a combination of Fat-pin tubes and WEIRD early metal shell octals, and as a cherry on top the volume control is a pair of coils that are mechanically moved in relation to each other to control the volume (I really need to see the schematic to sate my curiosity).
Radios did start to loose challenge and mystery to me, which is when I got into TVs, and those gave me all I could ask for and more for a while. I'm better and don't get as much challenge now, but TVs by nature make you keep using your head for repairs.
I'm starting to get to the point of scratch building things (like audio equipment) now. It used to be I lacked the math and understanding to make much of anything that worked or was useful, and preferred to fix equipment with good designs and tech info, but now that I can design from scratch that can be fun too (though sometimes frustrating).