I've had a few hobbies over the years that were geeky, but that I no longer spend any time on. Building computers is very close to falling into that category.
As a kid, my chief hobby was electronics. I was also a part-time musician for several years, and then I used to obsess about listening to music (not just HiFi equipment, but collecting the music and experiencing it in an ideal environment).
All of that's fallen by the wayside now, although I'm planning to dust off the soldering iron and build an IR beam alarm for my garage (from a kit - I've no interest in spending time on it).
Cars used to be a hobby, i.e. modifying them in useful ways. These days, it's too expensive and I don't believe there's anywhere near as much point. Cars in general have far better dynamics and engines than they used to, our cities are more congested, and around here we have Speed Cameras.
Actually, cars are probably still a bit of a hobby, in terms of trying to get them fixed right, selecting the best tires, etc.
But I now see them more as a means of getting from A to B, and how much money I can save in running costs.
For the last 20-odd years, I've been interested in the thermal characteristics of buildings (every few years it has practical application!). Air conditioning design has become an interest as well (hands up those who know what latent capacity is and what effect it has in different climates).
Lighting has also been a long-term interest. An offshoot of that is my current obsession: flashlights (or torches to everyone outside the US).
At work, I'm trying to decipher a couple of 200,000 line programs that have no documentation. This weekend, I'm going to try again to make sense of a 50,000 line program for a client and fix it so I can actually bill them. My attitude towards programming has become not dissimilar to Merc's. The odds of me doing anything in assembler as a hobby are somewhere between nil and null.
I take my hat off to someone who still has the enthusiasm to do what you've done, Chewy.