What other hobby...

I got into antique jukeboxes around 1990. Buying, restoring, selling, collecting, etc.  I'd be up untill 3 am working on them.  I had nine at one point, I have three favorites now.  I joined the American Historical Jukebox Society.  Meetings, a newspaper, jukebox shows, jackets, the whole works. I met guys with so many jukeboxes they had no room for furniture. I still love those darn things I just don't put in that much effort these days. It was great fun, no regrets. 

I'm with oldheavymech in that I have a lot of gas still in the tank.  That said...
Downhill skiing.  I enjoy the art of tuning my skis and getting the most out of them.  Quick, sharp, and precise turns that secure the most g-force.

Offshore fishing.  It takes a lot of trial & error, and patience, to get those elusive bluefin tuna.  But when you do, especially the bigger ones at between 60 to 150 lb., what a thrill and what a reward.  All other pelagic species are a great catch too, but those bluefin tuna are the best thrill of them all.

Hand loading ammunition for competition.

Bears, Beets, Battlestar Galactica.

I was thinking in terms of the self becoming the infinite hobby. None of you guys up for the contemplative life where the focus turns to what is doing the all the hobbies, all the seeking and avoiding? Whatever taste I've had of delusions dissolved by deepening understanding, and I've certainly had my share of delusions in this life, just makes me want more. I'm up for trading some of my tinkering time for meditation.